Heat the oven to 325°F and line an 8x8-inch pan with parchment paper. Combine the almond flour and softened butter in a bowl until the mixture forms a cohesive dough. Press the dough across the pan in an even layer, then bake for about 10 minutes until the edges are lightly golden and the center feels firm.

Leave the baked shortbread in the pan until it has cooled completely. The crust should feel solid rather than warm before it meets the caramel.

Melt the 5 tbsp salted butter in a saucepan over low heat, stir in the allulose until dissolved, then add the heavy cream and raise the heat to medium. Simmer for 10–15 minutes, stirring occasionally, until the caramel is thick and golden. The caramel may foam while it cooks; the bubbles settle as it cools, and the sauce becomes more viscous as it stands.

Spread the cooled caramel evenly over the cooled shortbread and refrigerate for 45 minutes to 1 hour, until firm. Lift the set slab from the pan, cut it in half, then cut each half into 10 bars for 20 total. The caramel should hold its shape cleanly at the cut edges instead of flowing or pulling away from the crust.

Dip each chilled bar in the melted sugar-free chocolate, then place it on wax or parchment paper and refrigerate until the coating sets. The chocolate should become firm and opaque around the cold caramel layer.