Preheat the Oven- Preheat your oven to 325°F and line a large baking sheet tray or cookie sheet with parchment paper.
Mix the Dry Ingredients- In your stand mixer or large bowl, add all the dry ingredients — almond flour, whey protein powder, monk fruit sweetener, baking powder, and salt. Blend on low speed until everything is evenly combined.
Add the Wet Ingredients- Pour in the melted butter, almond extract, anise extract, liquid stevia, and beaten eggs. Blend again until a dough forms. It will seem slightly sticky — that’s okay.
Stir in the Toasted Almonds- Using a spatula, stir in the sliced almonds. Transfer the dough to your prepared baking sheet.
Shape the Dough- With slightly wet hands, form the cookie dough into a rectangle about 10 inches long and 6 inches wide. Keep the edges smooth and even so the biscotti bake uniformly.
First Bake (The “First Time” Bake)- Bake in preheated oven for 25 minutes, or until lightly golden brown on top. Let the loaf cool for 30 minutes — do not rush this step!
Slice the Biscotti- Place the loaf on a cutting board. Using a sharp serrated knife, slice into 1-inch pieces. Press gently and saw slowly to avoid breaking the crunchy cookie edges.
Second Bake (Cut-Side Down)- Place each biscotti slice on the baking tray cut side down.Bake the second time for 10 minutes, flip carefully, and bake another 10 minutes. Cool Completely- Transfer the biscotti to a wire rack. They will continue to crisp as they cool.
Store the biscotti in a sealed airtight container for: 2–3 weeks at room temperature or Up to 3 months in the freezer.To re-crisp them, place in a 300°F oven for 5 minutes.