Fudgy 100 Hour Brownies Recipe

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Hi Bold Bakers!

WHY YOU’LL LOVE THIS RECIPE: Make our Fudgy 100 Hour Brownies Recipe for a life-changing version of this classic chocolate treat! They’re wonderfully gooey with exceptional mouthfeel. Don’t let the “100-Hour” part scare you–this is a mostly hands-off recipe!  

• Transcendent flavor: Bittersweet chocolate, dark brown sugar, and Rodelle Pure Madagascar Bourbon Vanilla Extract create a trifecta of rich flavor. I’m thrilled to partner with Rodelle on this recipe because it’s the best for baking and elevates a recipe to greatness. Rodelle Pure Madagascar Bourbon Vanilla Extract is exceptional here, with its delicious layered complexity containing notes of subtle warm cinnamon and marshmallowy sweetness.
• Viral for a reason!: It’s our mission to give you our BEST tested (and re-tested!) recipes. If there’s a new viral baking technique or hot ingredient, we test it thoroughly, and we never share it unless it’s exceptional. Fudgy 100-Hour Brownies absolutely live up to the hype, like our own Bigger Bolder Baking viral recipes, including Easy Homemade Ice Cream No Machine, Best-Ever Cinnamon Rolls, and 1-Minute Microwave Mug Cakes.

Vanilla is such a crucial element in baking–it beautifully accentuates other ingredients and brings its own exquisite taste. I chose Rodelle Pure Madagascar Bourbon Vanilla Extract for this recipe because it is the best choice for flavor, quality, and value. Rodelle has nearly 100 years of tradition and vanilla expertise, bringing carefully crafted extracts to consumers across the world. All Rodelle vanilla products are superior because they’re expertly blended from the finest vanilla beans, ensuring that every batch is outstanding. Use Rodelle in all Bigger Bolder Baking recipes, including Irresistible S’mores Bars, Peanut Butter and Jelly Cookies, and Strawberry Cheesecake Ice Cream. Rodelle Pure Madagascar Bourbon Vanilla Extract is a premium product at a great price and is available in stores and online, making it even easier to find.

Table of Contents

• What are Fudgy 100-Hour Brownies?
• Tools You Need
• Key Ingredients and Why
• How to Make 100 Hour Brownies Recipe
• Gemma’s Pro Chef Tips
• Make Ahead and Storage Instructions
• FAQs
• More Brownie Recipes

What are Fudgy 100 Hour Brownies?

• Our Fudgy 100-Hour Brownies Recipe gives you a batch that’s extra moist and delectably dense, with a flawless crinkly crust studded with melty bittersweet chocolate. This recipe uses the technique of aging, or resting, the dough to hydrate it and develop the flavor so it melds into a chocolate candy-bar-like intensity. 
• The batter rests for three days before baking, and you chill the cooked brownies for one day. It may seem like a long wait, but this easy hack will really up your brownie game! And this brownie recipe takes only 20 minutes to prepare and just 40 minutes to bake. The extended fridge time is the magic that transforms these brownies into a next-level indulgence.
• Resting the batter and then the finished brownies vastly improves their taste and texture. The flour will also absorb more moisture to create a fudgier texture (and make the top extra glossy, too). And during the aging process, moisture evaporates, leaving you with concentrated flavor. They’re worth the wait!
• This Fudgy 100 Hour Brownies Recipe is our version of the internet-sensation recipe that flips the typical brownie-making script by aging the dough for four days. Alvin Zhou, a producer for BuzzFeed’s Tasty videos, created the viral video for 100-Hour Fudgy Brownies. Here, we used our own brownie recipe and followed his technique!

Tools You Need

• Mixing bowls
• Measuring cups
• Measuring spoons
• Glass measuring jug
• Kitchen scale (optional)
• 8-inch square (20-cm) pan
• Parchment paper
• Double boiler (optional)
• Whisk
• Aluminum foil

Key Ingredients and Why

Bittersweet chocolate

• Bittersweet chocolate gives these brownies exquisite depth and richness. Some of the chocolate is melted with butter in the batter, and the rest is chopped and scattered across the top to add an irresistible chunky, melty texture.
• My go-to chocolate for baking is bittersweet. With a cocoa-solid percentage ranging from 63 to 72%, it’s wonderfully bold, and It has the perfect balance.
• Learn all about the different kinds of chocolate and their tastes, textures, and uses in The Ultimate Guide to the Different Types of Chocolate.

Butter

• Butter, which is 80 to 85% fat, gives this fudge brownies recipe unparalleled richness. Melting the butter with the bittersweet chocolate gives the brownies a lovely, gooey texture that becomes almost ganache-like!
• Importantly, butter gives a rich, creamy flavor.

Eggs

• Eggs emulsify the ingredients, bringing them together in a cohesive whole and holding the batter together.
• The eggs lift the brownies, keeping the texture from being overly heavy.
• Unless otherwise specified, always use room-temperature eggs in baking. Room-temperature eggs blend better with the other ingredients and won’t cause the melted butter and chocolate to seize. Here’s how to warm up eggs.

Dark brown sugar

• Brown sugar adds both sweetness and moisture to brownies. Because it contains molasses, it gives your brownies lovely, rich caramel notes.
• Mixing sugar with melted butter and chocolate gives the brownies their characteristic crinkly tops.
• Make your own brown sugar with my easy recipe.
• I don’t pack brown sugar for brownies. For the most accurate measurement, go by weight if you have a kitchen scale.

Rodelle Pure Madagascar Bourbon Vanilla Extract

• Rodelle Pure Madagascar Bourbon Vanilla Extract adds delicious notes of sweet creaminess and mellow spice to these fudgy brownies.
• Additionally, Rodelle Pure Madagascar Bourbon Vanilla Extract has an enticing aroma that enhances the brownies and makes your kitchen smell heavenly!

Salt

• Salt adds depth of flavor to the brownies by enhancing the other ingredients.
• Use plain table salt, or you can use fine sea salt in the same amount.

All-purpose flour

• All-purpose flour gives the brownies structure.
• Because all-purpose flour has a protein content of 9-11%, it has enough gluten to hold the mixture together but give you wonderfully fudgy brownies.

How to Make Fudgy 100 Hour Brownies Recipe

Prepare to bake

Gemma’s Pro Chef Tips

• For the best brownies, use bittersweet chocolate when making the batter. Semisweet or milk chocolate does not have a full enough flavor. However, either milk or semisweet chocolate can be used for the topping.
• If you don’t have time to wait the full 100 hours, you can bake the brownies sooner. Even 24 hours of aging will improve the texture!
• These brownies are extremely rich, and a little goes a long way. If you prefer, they can be cut into 16 smaller squares.
• Be careful not to overbake your batch of brownies! They’re perfectly cooked when the brownies are firm around the edges but still soft and JUST set to the touch in the middle (no longer jiggling). A knife inserted in the center should come up with some very moist crumbs attached, but not wet batter.
• A brownie this sophisticated would be perfect with a scoop of Coffee Gelato, or use one of these heavenly brownies to make an affogato sundae: place a warmed brownie in a bowl with a scoop of 2-Ingredient Vanilla Ice Cream and pour a shot of espresso over the top.

Make Ahead and Storage Instructions

• Planning ahead to make Fudgy 100 Hour Brownies Recipe:

  • Make the brownie batter and refrigerate three full days (72 hours) before baking.
  • You can refrigerate the batter longer, but for no more than five days.
  • Note that the brownies are chilled for one day after baking. These brownies take four days from start to finish. 

• Storing leftovers:

  • Store leftovers in an airtight container at room temperature for up to three days.
  • For longer storage, wrap well in plastic wrap, place in a freezer bag or airtight container, and freeze for up to four weeks. 

FAQs

• Can I bake this 100 hour brownies recipe in a different-sized pan?

  • Yes, you can bake this 100 hour brownies recipe in a different-sized pan. Just note that:
    • If you use a bigger pan, your brownies will be thinner and will take a few minutes less in the oven than the recipe calls for.
    • If you use a smaller pan, the brownies will be thicker and may take a few minutes more to bake.
    • And take care not to overbake your brownies! You know when your brownies are perfectly cooked when they’re firm around the edges, but they’re still soft and JUST set to the touch in the middle. A knife inserted in the center should come up with some very moist crumbs attached, but not wet batter.

• Can I make these brownies gluten-free?

  • Yes, you can make these brownies gluten-free. Use a 1:1 gluten-free blend in place of the all-purpose flour.
  • For another great gluten-free brownie option, check out our Gluten-Free Almond Flour Brownies recipe made with our versatile Almond Flour Baking Mix.

• Can I make this Fudgy 100 Hour Brownies Recipe without eggs?

  • Yes, you can make Fudgy 100 Hour Brownies without eggs. Check out our guide to  The 12 Best Egg Substitutes for Baking and How to Use Them.

More Brownie Recipes

• Simple Stovetop Brownies
• Cream Cheese Brownies
• 1 Minute Microwave Brownies in a Mug
• Caramel Brownies
• Banana Bread Brownies

Try These Recipes!

Irresistible S'mores Bars Recipe

Gluten-Free Almond Flour Brownies Recipe

3-Layer Apple Pie Blondies Recipe

2-Minute Microwave Brownie Bowl