Preparation Steps

• Make the filling: In a small skillet or saucepan, melt the 3 tbsp butter over medium heat until it foams and just turns lightly golden, 2 to 3 minutes. Immediately pour into a bowl to cool slightly (3 minutes). Whisk in the granulated sugar, egg yolk, vanilla, almond extract, and a pinch of salt until glossy. Stir in the ground almonds and flour until smooth. Let the mixture rest 10 minutes to thicken, then transfer to a small piping bag or zip-top bag (snip a small corner).
• Heat the oven to 360°F. Line two baking sheets with parchment paper.
• Whisk the dry ingredients for the dough: In a medium bowl, combine the all-purpose flour, baking powder, baking soda, salt, and ground almonds until evenly distributed.
• Cream the butter and sugars: In a large bowl, rub the orange zest into the brown sugar and granulated sugar with your fingertips until fragrant. Add the softened butter and beat with a hand mixer on medium-high until pale and fluffy, about 2 minutes.
• Beat in the egg yolks, vanilla, and almond extract until the mixture looks thick and creamy, scraping down the bowl as needed.
• Add the dry mixture to the bowl and mix on low just until a soft dough forms; do not overmix.
• Shape and fill: Scoop the dough into 18 portions using a level 2-tbsp scoop. Roll into balls, then press each into a 2-inch disk on the prepared sheets. Flour your thumb or use a 1/2-tbsp measure to make a deep well in the center. Pipe about 2 teaspoons of almond filling into each well and gently nudge the dough edges up to form a slight rim. Press sliced almonds over the tops and around the edges.
• Chill the trays for 15 minutes (or freeze for 8–10 minutes) to help the cookies keep their shape.
• Bake 6 cookies per sheet for 12–14 minutes, until the edges are just turning golden and the centers look set but still soft. If needed, immediately nudge the hot cookies into perfect circles using a large round cutter or an upside-down glass.
• Cool on the pan for 5 minutes, then transfer to a wire rack to cool completely. Sift powdered sugar over the tops right before serving.