Stir in milk, sugar, 3 tbsp melted butter and salt; add flour.

Mix on medium speed until a stiff dough forms, about 5-7 minutes.

Transfer to a work surface and form into a square; wrap in plastic wrap and refrigerate for 2 hours.

Place remaining butter on a sheet of plastic wrap or parchment; cover with another sheet.

Using a rolling pin, pound and shape butter into a 6”, ½”-thick square; set aside.

Using rolling pin, roll dough into an 16” square on a lightly floured work surface.

Unwrap butter square, and place on dough so its corners line up with the middle point of each side of dough square; fold dough corners over butter so they meet in the center.

Roll dough into a 12” x 9” rectangle, and then tri-fold dough like a letter.

Roll the dough into a 12” x 9” rectangle and repeat folding.

Wrap in plastic wrap; chill for 30 minutes to 1 hour.

Repeat rolling and folding dough twice more; chill for 1-2 hours.

Roll dough into a 20” x 14” x ¼” thick sheet; halve lengthwise.

Cut each half into about 9 triangles, about 3 ½”-wide at their base; cut a ½”-deep slit in the middle of each wide base.

Place 1 chocolate bar parallel to the base near the cut; holding the tip of the opposite corner down, roll the base over the chocolate toward the tip until it forms a tight roll.

Place croissant on a parchment paper-lined baking sheet, tip side down, and brush with egg wash.

Repeat with remaining triangles, bars, and egg wash.

Let croissants sit until doubled in size, about 2 ½–3 hours. For regular croissant, simply omit the chocolate.

To make more traditional pain au chocolat, cut 3 ½” wide rectangles from each 7” strip.

Place first chocolate piece at bottom of rectangle.

Roll over once.

Place second chocolate piece and roll over again.

Place on parchment-lined sheet keeping seam at the bottom.

Working with one baking sheet at a time, brush croissants with more egg wash.

Bake until deep golden brown, about 20-24 minutes.

Enjoy!