In a medium saucepan over medium heat, combine sweetened condensed milk, light brown sugar, unsalted butter, light corn syrup, and fine salt. Stir constantly until thickened, about 10-12 minutes. Remove from heat, stir in vanilla extract, and let cool.

In a small saucepan, heat heavy whipping cream until just simmering. Pour over dark chocolate chips in a heatproof bowl, let sit for 5 minutes, then stir until smooth. Add unsalted butter, mix, and allow to cool.

In a mixing bowl, combine softened butter, all-purpose flour, and powdered sugar. Mix until a soft dough forms. Chill for 30 minutes, roll out to 1/4-inch thick, cut into discs, and bake at 350°F for 10-12 minutes until golden. Let cool and crumble.

Preheat oven to 315°F and line baking sheets. Whip aged egg whites until soft peaks form. Gradually add superfine sugar, continuing until stiff peaks. Sift together almond flour and powdered sugar, fold gently into egg whites until flowing.

Transfer batter to a piping bag fitted with a round tip. Pipe 1 1/4-inch rounds on sheets, tap to release air. Rest for 30-60 minutes until a skin forms.

Bake for 17-21 minutes until shells are firm and lift off parchment easily. Cool completely on sheets.

Pair similar sized shells, pipe ganache on one, sprinkle crumble in center, pipe caramel on opposite half, press together.

Refrigerate assembled macarons in an airtight container for at least 24 hours. Before serving, let sit at room temperature for 30 minutes.