In a food processor add slivered almonds (and coconut flakes if using). Pulse until almonds are about ⅓ of the original size. Transfer to a bowl and set aside.
Add almond flour, coconut flour, erythritol, baking powder and salt to the processor bowl. Pulse until combined.
Once mixed, add the vanilla, stevia, and egg, pulsing until combined. Add chunks of butter and pulse until just combined.
Reserve 2 tablespoons of the coconut/almond mixture. Add the rest of the coconut and almonds to the dough and mix until combined.
Preheat oven to 375F. Line a baking sheet with parchment or silicone liners.
Use a cookie scooper to form 12 balls on the lined baking sheet.
Flatten balls a little bit with the palm of your hand, they will spread slightly when baked. Then sprinkle the remaining 2 tbsp of coconut and almonds on top of the cookies. Lightly press in the topping.
Bake for 8-10 minutes until golden brown. You can flatten the cookies more with the bottom of a glass once they come out of the oven if desired.