Preheat oven to 300°F and line two baking sheets with parchment paper.
Sift together powdered sugar and almond flour to remove lumps.
Beat egg whites until foamy, then gradually add granulated sugar and beat until stiff peaks form.
Gently fold dry ingredients into the meringue until the batter flows like lava.
Pipe 1-inch circles onto baking sheets and let sit for 30 minutes to form a skin.
Bake for 14-16 minutes until firm. Cool completely before filling.
For buttercream, beat butter until creamy, then add powdered sugar, strawberry puree, and vanilla extract.
Pipe filling onto half the macarons and sandwich with the other halves.
Let macarons rest in the fridge for 24 hours for best texture.