For macaron shells
Line a cookie sheet with a silicone mat or parchment paper
Using a food processor, pulse the Powdered Sugar and almond flour until fully combined and rid of lumps. Sift the combined dry ingredients into a large bowl. If you do not have a food processor you can just sift the ingredients.
In a medium bowl, prepare the French meringue. Beat the egg whites on low speed with a hand mixer until they get frothy. Increase the speed and slowly add the Granulated Sugar. Beat until stiff peaks form. If you want to add food coloring, do it now, but use it sparingly or you will make the meringue too liquidy.
Add the dry ingredients to the French meringue and begin to gently fold. The batter should be fully combined and not streaky. When you are able to make a figure 8 with the batter in one motion, the batter is ready. If it is too runny it has been over-mixed.
Transfer the batter to a piping bag fitted with a piping tip. Pipe 1-inch disks on to the prepared mat or parchment.
Tap the cookie sheet on the countertop 3 or 4 times to get rid of any air bubbles. Use a toothpick to pop any remaining air bubbles.
Allow the macarons to rest for an hour or until the tops of the macarons have dried. You will be able to gently run your finger over them without anything getting on your finger.
Preheat the oven to 300°F.
Place the macarons on the middle rack of the oven and turn the oven down to 280°F. Bake for 5 minutes, rotate the cookie sheet and bake for another 5 minutes, rotate the pan one last time and bake for 5 minutes. 15 minutes in total.
Remove from oven and allow to cool completely on the cookie sheet.
If the macarons were baked correctly they should easily peel off of the silicone mat.
For the Ganache
In a small saucepan heat the heavy cream over medium heat. Place the chocolate in a medium bowl.
When the cream comes to a light boil turn the heat off and pour the cream over the chocolate. Allow to sit for 5 minutes.
Use a whisk to slowly stir the ingredients together until the chocolate is fully melted.
Cover the surface of the ganache with plastic wrap. Place in fridge unit fully cooled and thickened.
For Pecan Pie Filling
In a small saucepan combine the butter and Light Brown Sugar. Place over medium heat until very bubbly, about 3-5 minutes.
Add the salt, heavy cream, vanilla, and pecans. Stir until well combined.
Remove from heat and allow to cool for at least 10 minutes.
Match each macaron shell up with a similarly sized shell.
Transfer the ganache to a piping bag fitted with a piping tip and pipe a circle of ganache around the edge of the inside of one macaron shell, leaving a space in the center.
Spoon your desired amount of pecan pie filling into the space in the center.
Place another macaron shell on top.