Preparing the Shells:

1. Prep Your Baking Sheets: Line two large baking sheets with parchment paper or silicone baking mats.
2. Mix Dry Ingredients: In a food processor, pulse powdered sugar, almond flour, and salt until fine and combined. Transfer to a large bowl.
3. Whip the Egg Whites: Using a mixer with a whisk attachment, beat the egg whites until soft peaks form. Gradually add granulated sugar until stiff peaks develop.
4. Add Strawberry Flavor: Gently fold in strawberry puree or jam into a portion of the meringue, then carefully fold this back into the main mixture.
5. Combine Dry and Wet Ingredients: Fold the dry mixture into the egg whites in increments until just combined.
6. Preheat Oven to 350°F (175°C).

Piping and Baking:

1. Pipe the Batter: Fill a pastry bag with half of the batter and pipe onto prepared sheets in walnut-size mounds, spaced 3 inches apart.
2. Remove Air Bubbles: Tap the sheets against the counter to release air bubbles.
3. Bake: Bake each sheet individually for about 14 minutes, rotating halfway for even cooking. Slide the parchment off the baking sheet to cool.

Making the Filling:

1. Cream the Butter: In a mixer, cream the butter until smooth.
2. Add Sugar and Flavor: Beat in powdered sugar, vanilla, and strawberry puree until fluffy.
3. Prepare for Assembly: Transfer the filling to a piping bag with a small round tip.

Assembly:

1. Pair the Shells: Match similar-sized shells.
2. Pipe the Filling: Pipe a small amount of filling on one shell and sandwich with another.
3. Enjoy the Imperfections: Some macarons might not turn out perfect, but they’re great for taste testing!