Combine the ⅔ cup sliced almonds and 2 teaspoon sweetener in a food processor and pulse into chopped. Transfer to a small bowl and set aside.
Next, combine all the dough ingredients in the food processor and pulse until a uniform dough forms. Divide into 24 balls and roll each in the almond topping. Put on a parchment lined baking sheet and press down making a little well with your thumbs. Sprinkle a little more almond topping on each.
Bake for 12-15 minutes or until lightly browned around the edges. Cool for at least 10 minutes.
Meanwhile, put the chocolate chips and heavy cream in a microwave safe bowl and heat for 30 seconds. Stir. Heat for another 30 seconds. Stir. Repeat until the chocolate has melted. Stir until smooth.
Divide the chocolate ganache between the thumbprint cookies. Sprinkle with a little more of the chopped almonds.