In a small bowl, whisk together the almond flour, powdered sugar and lemon zest.
In a large bowl with an electric beater, beat the egg whites and vanilla until foamy. Slowly beat in the granulated sugar and continue to beat on high until it has reached soft peaks (when you lift the beater out the ends of the egg whites should curl, it may take a while of beating).
Gently fold in the dry ingredients until just combined.
Scoop the batter into a large pastry bag attached with a large round tip or a ziploc with a hole cut out of one end. Pipe out 1 tablespoon-sized circles, spaced one inch apart on a silicone mat or parchment paper covered baking sheet.
Tap the baking sheet a few times to get the air bubbles out. Allow them to sit out at room temperature for 30 minutes.
Preheat the oven to 325°F. Baking one sheet at a time, bake for 8-10 minutes until hardened but not light brown. Allow them to cool completely on the baking sheet on a cooling rack before slowly peeling back from the silicone or parchment.
Beat the filling ingredients together with a spoon until combined. Match up like macaron shells and place a spoon full of filling between the shells to make a sandwich. Store in an airtight container.