01 - Whisk together gluten-free flour, almond flour, sugar, yeast, and salt in a large mixing bowl until thoroughly combined.
02 - In a separate bowl, blend warm milk, warm water, egg, and softened butter. Pour the wet mixture into the dry ingredients and mix until a sticky dough forms.
03 - Shape the dough into a rectangle, wrap tightly in plastic wrap, and refrigerate for 45 minutes to allow the gluten-free structure to set.
04 - Slice cold butter into thin slabs. Place between parchment paper sheets and pound or roll into an even 6 x 8-inch rectangle. Return to refrigerator if too soft.
05 - Roll chilled dough on a lightly floured surface into a 12 x 8-inch rectangle. Position butter layer over bottom two-thirds of dough, leaving a border. Fold top third down over butter, then fold bottom third up (letter fold).
06 - Rotate dough 90 degrees. Roll to 12 x 8-inch rectangle and repeat letter fold. Perform rolling and folding process two additional times, chilling for 20 minutes between each turn to maintain proper temperature.
07 - Wrap dough and refrigerate for 1 hour after completing the final fold to relax the dough before shaping.
08 - Roll dough into a 16 x 10-inch rectangle. Cut into 8 equal triangles using a sharp knife or pizza cutter. Starting from the wide end, roll each triangle tightly to form traditional crescent shape. Place point-side down on parchment-lined baking sheet.
09 - Cover loosely and let rise in a warm, draft-free area for 1 to 1 1/2 hours until slightly puffy and increased in volume.
10 - Preheat oven to 400°F. Whisk egg and milk for egg wash. Brush croissants lightly and evenly with the mixture.
11 - Bake for 20 to 22 minutes until deep golden brown and flaky. Allow to cool slightly on the baking sheet before serving.