01 - Line two baking sheets with parchment paper or silicone mats. Fit a piping bag with a round tip measuring approximately 0.4 inches in diameter.
02 - Combine almond flour and powdered sugar in a food processor and pulse until extra fine. Transfer to a large bowl and sift, discarding any coarse particles.
03 - In a clean, grease-free bowl, whip egg whites and cream of tartar until foamy. Gradually incorporate granulated sugar while whipping until stiff peaks form. Add pink gel food coloring and mix until evenly distributed.
04 - Gently fold the sifted almond mixture into the meringue in three additions using a spatula. Continue folding until the batter achieves a lava-like consistency with thick ribbon formation. Avoid overmixing.
05 - Transfer batter to the prepared piping bag. Pipe 1.2-inch rounds onto the prepared sheets, spacing approximately 0.8 inches apart. Tap trays firmly on the counter to release air bubbles and remove any visible bubbles with a toothpick.
06 - Allow macarons to rest uncovered for 30 to 45 minutes until the tops are completely dry to the touch.
07 - Preheat oven to 300°F. Bake one tray at a time for 12 to 15 minutes, rotating halfway through. Shells should develop feet and remain unbrowned. Cool completely on trays before removal.
08 - Beat softened butter until creamy. Gradually add sifted powdered sugar and mix until light and fluffy. Fold in strawberry puree, vanilla extract, and salt. Beat until smooth.
09 - Pipe or spoon buttercream onto half of the macaron shells. Top with remaining shells to form sandwich pairs.
10 - Refrigerate assembled macarons in an airtight container for at least 24 hours before serving. Bring to room temperature before consuming.