Preheat the oven to 350°F.

Combine all ingredients and mix well until a dough forms.

Press tablespoon volumes of dough into non-stick mini muffin tins and smooth down. You can also flatten the tablespoons of dough with the bottom of a drinking glass on a parchment-lined baking sheet.

If you would like to add a filling, such as sugar-free chocolate chips, use a teaspoon to form a depression. Add filling such as chocolate or jam. You can also leave the thumbprint empty and fill post-baking, again with a ganache, jam, curd, or caramel.

Bake 15-20 minutes if baking in a muffin tin and 10-12 minutes if you have opted to flatten the cookies on a baking sheet lined with parchment. They should be lightly golden. Remove cookies and allow them to cool completely on the pan/muffin tin.