Preheat and Prep: Preheat your oven to 350°F (175°C). Prepare a 9" tart pan by greasing the bottom and sides with butter.
Prepare Crust: Unroll the premade pie crust dough on top of the 9" tart pan. Gently press it into the bottom and sides of the pan. Cut the pie crust to fit the pan by using the back of a knife (or similar) and gliding along the outer edge of the tart pan.
Combine: To a medium bowl add ½ cup softened unsalted butter, 2 teaspoons pure vanilla extract, ¼ teaspoon almond extract, and 1 cup sugar. Mix with an electric mixer until creamy. Add 2 room temperature eggs and mix again until well combined.
Add Dry Ingredients: To the butter mixture add 2 cups almond flour, 1 tablespoon all-purpose flour and mix again until fully combined into a creamy paste.
Fill Tart: Transfer the frangipane filling to the prepared baking pan, and spread into a smooth even layer on top of the pie crust.
Top: Cover the top of the frangipane with ¾ cup sliced almonds in an even layer.
Bake: Place the tart in the oven and bake at 350°F (175°C) for about 30-minutes. The crust should be lightly golden brown and some of the almonds will begin to darken to a light brown color.
Cool and Serve: Carefully remove from the tart from the oven and set aside to cool to room temperature. Sprinkle with powdered sugar, slice, and enjoy!
