Line a baking sheet with a silicone baking mat or parchment paper.

Use a food processor to pulse the powdered sugar, almond flour until fully combined and rid of lumps. Sift the combined ingredients into a large bowl. If you do not have a food processor you can just sift the ingredients together. Set aside

In a medium bowl, beat the egg whites on low speed until they start to get foamy. Slowly add the granulated sugar and increase the speed. Beat the mixture until stiff peaks form.

Add the meringue into the dry ingredients and use a silicone spatula to gently fold the two together. The batter should be fully combined and not streaky. The batter is ready when it falls off of the spatula in a thick ribbon. It should not be too runny.

Transfer the mixture to a piping bag fitted with a piping tip. Pipe about 1-inch disks onto the prepared baking sheet.

Firmly tap the baking sheet 5 or 6 times on the counter to bring any air bubbles to the surface. Use a toothpick to pop any remaining bubbles.

Let the macarons rest for at least 1 hour. You should be able to gently run your finger over the surface of the macarons without any getting on your finger.

Preheat your oven to 325°. Place the baking sheet on the center rack of the oven and bake for 15 minutes, rotate the pan every 5 minutes to ensure even baking and coloring.

Remove the macarons from the oven and allow to cool completely on the baking sheet.

Gently peel each cooled macaron off of the mat and match up with a similarly sized cookie.

In a medium heat-proof bowl whisk together the sugar, lemon juice, egg, and egg yolk.

Place the bowl over a small saucepan of simmering water and add the cubed butter.

Let the mixture cook over low heat for about 15 minutes, whisking occasionally.

The lemon curd is ready when it hits 180 degrees (F) or is a very thick consistency.

Remove the curd from the heat and cover the surface of the curd with plastic wrap. Place the curd in the fridge until fully cooled.

In a medium bowl use a hand mixer to whip the heavy cream to stiff peaks. Be sure not to overwhip.

When the curd is cooled gently fold the curd into the whipped cream until fully combined.

Transfer the whipped lemon curd to a piping bag and pipe your desired amount onto the inside of a macaron shell. Sandwich another macaron shell on top.