• Preheat the oven to 350°F and butter a standard 12-cup muffin tin.
• Whisk the flour, ground almonds (or almond flour), baking powder, salt, and baking soda together; set aside.
• In a large bowl with a hand mixer or in the bowl of a stand mixer, cream together the butter and granulated sugar until light and fluffy; about 5 minutes. Beat in the eggs, one at a time, until mixed, then add the almond and vanilla extracts along with the sour cream.
• Fold in the flour mixture until just combined with no dry flour streaks.
• Spoon batter into prepared muffin tin. Fill each about halfway full.
• Bake 14 to 15 minutes or until the edges are lightly browned and a toothpick inserted in the middle comes out clean. Remove from the oven and immediately invert the pan to release the tea cakes. Let cool about 10 minutes before icing.

Make the Almond Icing

• Whisk powdered sugar, 1 tablespoon water (you can also use lemon juice or milk if desired), and the almond extract until smooth. Add additional water if needed to thin. Drizzle over tea cakes before serving and top with sliced almonds.