Place the dry ingredients in a food processor (almond flour, confectioner’s sugar and all-purpose flour). Pulse the mixture for a few minutes and then sift the ingredients into an extra-large bowl.
In the bowl of a stand mixer, add the egg whites and granulated sugar. Beat the mixture on high speed for 3-4 minutes, or just until stiff peaks form. Be extra careful not to over beat the eggs.
Add the egg whites to the dry ingredients, along with a few drops of the red food coloring. Using a spatula, begin to fold the flour into the egg whites. Keep mixing in a folding motion until the batter reaches the "lava stage" – the point where it drips slowly off the spatula.
Transfer the batter into a pastry bag topped with a round tip. Line two large baking sheets with parchment paper or silicone mats. Pipe 1-inch dollops of batter onto the baking sheets, spacing them about an 1 ½-inches apart. Once the baking sheet is full, tap the pan a few times against the kitchen counter to release any trapped air bubbles.
Allow the macarons to rest for at least 1 hour, or until they form a thin, shiny shell on the outside. Preheat the oven to 320°F. Bake the macarons for 18 minutes. Allow the macaron shells to cool completely on the baking sheet.
Preparing the Filling
While the shells are cooling, prepare the white chocolate filling. Place the softened butter into a medium-sized bowl and beat it with mixer for a few minutes until light and fluffy. Add in the melted white chocolate. If the melted chocolate softens the butter too much, place the mixture into the refrigerator for 15 minutes and then mix it again.
Add the confectioner’s sugar, vanilla and salt. Mix on low speed until the sugar is incorporated, then mix it on high speed for 2-3 minutes until a fluffy buttercream forms. Add the 2 tablespoons of cranberry jelly last and mix for about 30 seconds, just until it’s incorporated.
Assembling the Macarons
Transfer the buttercream into a pastry bag with a star tip. Pair the macaron shells by size and pipe a ring of buttercream onto one half, leaving a small space in the center for the cranberry jelly. Using a small spoon, add a small dollop of the remaining jelly into the center of each macaron. Sandwich the cookies together and place onto a wire rack. If desired, melt ¼ cup white chocolate chips, transfer it into a pastry bag, and drizzle it over the cookies.
Place the macarons in an airtight container in the refrigerator for at least 1 day to allow them to mature. Take the macarons out of the refrigerator about 30 minutes before enjoying.