Preheat your oven to 325° F.

In a large mixing bowl, add all of the dry ingredients for your biscotti and mix to combine.

Melt the butter in the microwave for about 30 seconds.

Add the melted butter to the bowl along with your milk. I suggest adding milk 1 tablespoon at a time since different brands of protein powder and different types of milk can mix differently. Always better to use less and then add more as needed instead of finding out your dough is too wet! (¼ cup = 4 tablespoons).

Add the dough to a cookie sheet. IMPORTANT: A regular baking pan will lead to the bottom of the biscotti becoming very dark. The type of cookie sheet I recommend is here, and a great visual breakdown of why it matters can be seen at Handle The Heat).

Shape the dough into a log and flatten it down so it is about ½ inch thick (see photos above for reference).

Bake the biscotti at 325° F for 20 minutes, until the edges become golden brown.

Remove from the oven and let cool completely, about 20-30 minutes. Once cooled, carefully slice diagonally using a serrated knife to create your biscotti. It's very important that the biscotti is cooled at this stage or it will fall apart when you go to slice it.

Lay the biscotti flat on your cookie sheet and return to the oven at 325° for 6 minutes.

Flip the biscotti and bake for an additional 6 minutes to brown both sides. For extra crispy biscotti you can bake for up to 10 minutes per side.

Allow the biscotti to fully cool and crisp up, then dig in!