1. In the bowl of a stand mixer fitted with the dough hook attachment, add yeast, sugar, milk, flour and salt. Mix on low speed until a dough ball forms, then add softened butter. Knead dough on medium speed for 5 minutes. Cover bowl with a kitchen towel or plastic wrap and allow dough to rest for 45 minutes at room temperature, then place in refrigerator for 30 minutes.

2. Punch down dough, then place on lightly floured surface. Divide dough into 10 roughly equal pieces. Flour your work surface and the dough, then roll a piece into a 10 inch circle. The dough will be thin. Transfer dough circle to a piece of parchment paper. Spread a layer of softened butter over the dough circle, gently. Roll another dough piece into a 10-inch circle, then place on top of the butter layer. Spread a layer of butter over this dough circle. Repeat until all pieces of dough are used. Do not butter the top piece of dough.

3.  Slide the dough (which should be on parchment paper), onto a baking sheet. Cover the dough with plastic wrap and place in refrigerator overnight, or up to 24 hours).

4. Roll out stack of dough into a 16 inch circle. Using a pizza cutter, cut the dough into 12 roughly equal triangles. Cut a small slit in the wide edge/base of the triangle, then roll, starting at the wide edge/base triangle. Place, tip side down, onto a parchment paper lined baking sheet. Repeat with the rest of the triangles, placing them 2 inches apart. Cover the croissants with a kitchen towel or plastic wrap and allow to rise at room temperature for 1 to 2 hours, or until visibly puffy and jiggly.

5. Preheat oven to 400F. Using a pastry brush, brush the croissants, gently, with egg wash. Bake in preheated oven for 15-20 minutes, or until golden brown in color. Serve warm and enjoy!