Preheat your oven to 300°F (150°C) and line a baking sheet with parchment paper.
Sift the almond flour and powdered sugar together into a bowl. Set aside.
In a separate bowl, beat the egg whites until they form soft peaks. Gradually add the granulated sugar and continue to beat until stiff peaks form.
Gently fold the almond flour mixture and ground lavender into the egg whites until fully incorporated.
Transfer the batter to a piping bag and pipe small circles onto the prepared baking sheet.
Tap the baking sheet on the counter to release any air bubbles. Let the macarons sit at room temperature for 20-30 minutes until a skin forms on the surface.
Bake for 15-18 minutes, or until the macarons are firm to the touch. Allow to cool completely on the baking sheet.
For the filling, beat the butter until creamy. Gradually add the powdered sugar, honey, and vanilla extract, and beat until smooth.
Pair up the macaron shells by size and pipe the honey buttercream onto one shell. Sandwich with the other shell.
Store in an airtight container in the refrigerator for at least 24 hours before serving to allow the flavors to meld.