Preheat the oven to 350°F (175°C).

In a mixing bowl, combine the all-purpose flour and powdered sugar. Add the cold, cubed butter and mix until the mixture resembles coarse crumbs.

Add the egg yolk and cold water to the flour mixture, mixing until a dough forms. Press the dough into the bottom and up the sides of tartlet pans.

In another bowl, whisk together the almond meal, granulated sugar, eggs, melted butter, vanilla extract, and almond extract until smooth.

Pour the almond filling into the prepared tartlet crusts.

Top with sliced almonds.

Bake in the preheated oven for 25 minutes or until the filling is set and the crust is lightly golden.

Allow to cool before serving.