Set up 5 silicone cupcake molds on a large plate and set them aside. No need to butter them.

Into a sieve over a medium bowl, combine flour, sugar, 3/4 of the chocolate chips, cocoa powder, and baking soda.

In a separate measuring jug, whisk egg, yogurt, milk, oil, and vanilla until smooth.

Pour the wet into the dry chocolate mixture and stir until the batter is just blended. Fill prepared muffin cups 3/4 full and sprinkle with remaining 1/4 cup chocolate chips.

Microwave the muffins for 45 seconds, check and rotate on the plate, and microwave for another roughly 30 seconds-1 minutes. This timing is based on my microwave which is 1200 Watts so check the wattage of your microwave because your timing may vary.

Once your muffins have no more wet batter and they rise they are done. Set the muffins over to cool down and continue cooking off the rest of your batter.

The muffins are best enjoyed the day they are cooked. Store any leftovers in an airtight container at room temperature for up to 2 days. They can also be frozen for up to 4 weeks.