1 beaten egg yolk and 1 Tbsp water to make egg wash
Preheat oven to 375 degrees Fahrenheit, and lightly grease a cookie sheet or line it with parchment paper.
Using an electric mixer, beat butter until softened. Then add sugar, baking powder and combine them together well. Beat in 2 whole eggs and vanilla extract.
Fold in cocoa powder and flour. Stir in chocolate chips and nuts until they are just combined.
Divide dough in half and shape each portion into a 9 x 2 x 1 inch loaf. Place them on prepared cookie sheet and brush them with egg wash.
Bake for 20 - 25 minutes. Please note that the surface of these loaves may crack slightly while being baked. Cool them on baking sheet for 30 minutes.
When you are ready to bake them again, heat oven to 325 degrees F., then cut each loaf diagonally into ½-inch thick slices.
Place slices, cut side down, on cool cookie sheet. Bake for 10 minutes, then turn slices over and bake for another 10 minutes.
Remove from cookie sheet and cool on wire rack. Store in airtight containers. Brownie biscotti can be kept frozen for up to a month.
Bake for 20 - 25 minutes. Please note that the surface of these loaves may crack slightly while being baked. Cool them on baking sheet for 30 minutes.
Place slices, cut side down, on cool cookie sheet. Bake for 10 minutes, then turn slices over and bake for another 10 minutes.
