Preheat the oven to 350¡ãF and line a cookie sheet with parchment paper or a nonstick baking mat.
Use a mixer to cream the butter and sugar together. Add the egg and mix well.
In a medium bowl, whisk the flour, baking powder, and salt together.
Add the flour mixture to the butter mixture and mix on low until combined. Add the almond extract and mix well.
Use a cookie scoop to place about 1 tablespoon scoops of the dough on the cookie sheet about 3 inches part.
Bake for 8 to 10 minutes or until just starting to brown on the edges.
Cool on a wire rack.
For the drizzle:
In a small bowl, stir together the powdered sugar, almond extract, and heavy cream. Add additional heavy cream if it's too thick or additional powdered sugar if it's too thin to drizzle.
Drizzle the mixture over the cookies and sprinkle the toasted sliced almonds over the tops. Allow to dry before stacking.
