Step 1: Preheat and Prepare the PanPreheat your oven to 350°F (175°C). Line a 9×9-inch baking pan with parchment paper, leaving a bit of overhang on the sides. This makes it easy to lift the bars out once baked.
Step 2: Make the Shortbread BaseIn a mixing bowl, cream together ½ cup of softened unsalted butter and ½ cup of granulated sugar until light and fluffy. Add 1 egg, ½ teaspoon almond extract, and ½ teaspoon vanilla extract, and mix until well combined. Gradually add 1 cup of all-purpose flour and stir until a soft dough forms.
Press the dough evenly into the bottom of the prepared baking pan. Set aside.
Step 3: Prepare the Frangipane FillingIn a separate bowl, cream ½ cup of softened unsalted butter with ½ cup of granulated sugar until smooth. Add 1 egg, ½ teaspoon almond extract, and ½ teaspoon vanilla extract. Mix until combined.
Fold in 1½ cups of almond flour until the mixture is smooth and well incorporated, taking care not to overmix.
Step 4: Assemble the LayersSpread the frangipane mixture evenly over the shortbread base using a spatula or the back of a spoon. Smooth the top as evenly as possible.
Sprinkle ½ cup of sliced almonds over the frangipane layer. Gently press them into the surface so they adhere during baking.
Step 5: BakePlace the pan in the preheated oven and bake for 35–40 minutes, or until the top is golden brown and a toothpick inserted in the center comes out clean.
Step 6: Cool and ServeAllow the bars to cool in the pan for 15 minutes. Then use the parchment paper to lift them out onto a wire rack to cool completely.
Once fully cooled, dust with powdered sugar, slice into 16 bars, and serve.