FOR THE SHELLS:

1. Line 2 baking sheets with parchment paper or silicone baking mats (double up sheets if needed).
2. Process almonds and powdered sugar in a food processor until blended into a fine powder. Sift mixture into a large mixing bowl & set aside.
3. Combine egg whites & granulated sugar into the bowl of an electric mixer, fitted with the whisk attachment. Whip egg whites & sugar until stiff peaks, adding a little drop of the food coloring during about the last minute of beating the egg whites to make a tan color. (My perfect time is 2 minutes on speed 4, then 2 minutes on speed 6, & then another 2 minutes on speed 8 – they should stay put if you hold the bowl upside-down).
4. Add the dry mixture into the egg whites.
5. Using a spatula, smash dry ingredient into the egg white, flattening mixture (use about 5-10 quick strokes to release the air). Then fold mixture onto itself until it becomes shiny again (another 30-40 strokes). When you lift up the spatula, there should be solid, thick ribbons that run off (this whole macaronage process should take no more than about 50 strokes).
6. Transfer the batter to a large piping bag (I like to use a #12 round icing tip, but it’s optional).
7. Using circle guides or freehand, pipe about 1¼” circles onto the prepared baking sheets (they will spread to about 1½”), keeping them at least 1-2″ apart to allow for spreading. Do this same method for the second baking sheet.
8. Holding each end of the baking sheet, give it a good slam on the counter. Rotate the pan & give it another few slams to release any air bubbles that remain. Let the macs sit out for 30 minutes before baking to form a dry shell on the tops to prevent cracking.
9. Preheat the oven to 315 degrees F.
10. Bake each sheet, one at a time, for about 15-16 minutes (depending on size), rotating the pan once halfway through. Once they’re ready, carefully test one by attempting to lift it off the baking sheet. If the top half starts to come off from the feet, it could use a few more minutes.
11. Remove the sheet from the oven & place it on a cooling rack, allowing the cookies to cool before removing them. Once they are cooled, match up macarons in pairs that are about the same size, one face down & one up.

FOR THE FILLING:

1. Beat the butter on medium-high speed for 2 minutes with an electric mixer, fitted with the paddle attachment, until soft & fluffy. Add the powdered sugar, ½ cup at a time until combined (carefully incorporate). Mix in the cinnamon and the apple juice. Continue to beat on medium for another 1-2 minutes (Add up to a ½ cup more sugar if too thin or a little more juice if too thick).
2. Pipe a circle of the frosting around the edge the cookie that’s facing up. Next add a dab of the caramel in the center of the circle, topped with a little sprinkle of sea salt. Sandwich the halves together, pushing the filling to the edges.