Preheat your oven to 350°F (175°C) and line a baking sheet with parchment paper.
Prepare the almond filling: In a small bowl, mix together the softened butter, sugar, almond flour, almond extract, and a pinch of salt until smooth. Scoop into 8–10 small portions and place them in the freezer while you prepare the cookie dough.
In a large mixing bowl, beat together the softened butter, granulated sugar, and brown sugar until light and fluffy, about 2–3 minutes.
Add the egg, vanilla paste (or vanilla extract), and almond extract. Mix until fully combined.
In a separate medium bowl, whisk together the flour, baking powder, and salt.
Gradually add the dry ingredients to the wet ingredients, mixing until just combined. Scrape down the sides of the bowl as needed. Do not overmix.
Scoop the cookie dough using a large cookie scoop. Flatten each scoop slightly in your hand, place one frozen almond filling portion in the center, and wrap the dough around it until completely sealed.
Roll each dough ball in the sliced almonds, gently pressing so they stick. Place the cookies on the prepared baking sheet, leaving about 2 inches between each cookie.
Bake for 12–14 minutes, or until the edges are lightly golden and the centers are just set. Do not overbake—the cookies will continue to set as they cool.
Let the cookies cool on the baking sheet for 5 minutes before transferring them to a wire rack to cool completely.
Once cooled, dust generously with powdered sugar. For an extra bakery-style finish, sprinkle with a few extra toasted sliced almonds or drizzle with a light vanilla glaze.