Prep: Preheat your oven to 350°F (175°C). Prepare a 9×9 inch baking pan by greasing it and lining it with parchment paper.

Cream together: In a mixing bowl, add 1 cup softened butter and ¾ cup superfine white sugar, cream together until light and fluffy. Add 1 tablespoon pure vanilla extract and mix until fully incorporated.

Mix Dry Ingredients: In a separate bowl, whisk together 2 ½ cups all-purpose flour and ¼ teaspoon salt until combined.

Combine: Gradually add the dry ingredients to the butter mixture, mixing until just combined to avoid overworking the dough.

Press and Chill: Press about two-thirds of the dough into the prepared pan, reserving the remaining dough for the top layer. Refrigerate all of the crust for 15 minutes before baking.

Par Bake: Bake the crust in the preheated oven for about 15 minutes, until it's very lightly golden and no longer shiny on top. Avoid baking until golden brown, as it will be baked again. Allow crust to cool slightly while prepping the filling.

Combine: To a medium bowl add ½ cup softened butter, 2 teaspoons pure vanilla extract, ¼ teaspoon almond extract, and 1 cup sugar mix until creamy. Add 2 room temperature eggs and mix again until well combined. Add 2 cups almond flour, and 1 tablespoon all-purpose flour mix again until fully combined into a creamy paste.

Layer: Spread the frangipane on top of the prebaked shortbread crust in an even layer. Crumble the remaining shortbread on top of the frangipane in an even layer. Sprinkle 1 cup sliced almonds on top of the crumble.

Bake: Bake on 350°F (175°C) for about 35-37 minutes or until you see browned edges and some of the almonds begin to turn a shade darker. As oven temperatures can vary, it's a good idea to check on the Almond Croissant Bars before the 35-minute mark too.

Cool and Serve: Once baked, remove from the oven and let cool until the bars are room temperature. Sprinkle with powdered sugar, slice into bars and enjoy!