In a large bowl, whisk flour, baking powder, and salt together.

Stir in yogurt and knead for about a minute, until a smooth dough is formed.

On a floured surface, roll dough into an 8 x 12 inch (20 x 30 cm) rectangle.

Spread ⅓ of the butter over the dough. Fold the dough in thirds, like a letter, so that the dough is in 3 layers (see video above.). Cover and place in the fridge to chill for a minimum of 30 minutes.

Repeat this rolling, buttering, and folding 2 more times chilling for 30 minutes in between. Then wrap the dough in plastic wrap and refrigerate for 1 hour.

While the dough is chilling, preheat the oven to 375°F (190°C) and line a large baking sheet with parchment.

On a floured surface, roll the chilled dough into a large, thin rectangle, about 10x18 inches (25x45cm), cut in half lengthwise, and then cut each half into 4 squares.

Cut all 8 squares of dough in half diagonally.

For each crescent roll, gently stretch and roll a triangle of dough from the wide end to the tip and place on the prepared baking sheet with the tip under the roll.

When all the dough is rolled, brush with the egg wash and bake on middle racks in the oven for 30-35 minutes, until golden brown.

These rolls are best the day they are made but you can store any leftovers in an airtight container at room temperature for up to 3 days.