Preheat the oven to 180°C (350°F). Line a 24 cm x 16 cm (9.5" x 6.3") baking tray with parchment paper, leaving an overhang for easy removal.

Make the crust: in a large bowl combine 1.5 cups almond flour (150 g), 3 tablespoons allulose (34 g), 1 teaspoon vanilla extract, and a pinch of salt. Stir to combine, then add 4 tablespoons melted butter (57 g) and mix with a spatula until evenly moistened.

Press the crust mixture firmly and evenly into the bottom of the lined tray. Use the back of a spoon or a flat measuring cup to compact it.

Bake the crust for 15 minutes, or until lightly browned at the edges. Remove from the oven and let the crust cool completely in the tray (about 10–15 minutes).

Make the caramel: in a medium saucepan combine 1 cup cream (240 ml), 1/3 cup allulose (75 g), and 2 tablespoons butter (28 g). Bring to a gentle boil over medium heat, then reduce heat to medium-low and simmer, stirring regularly, until the mixture thickens and has reduced by about half (about 10–15 minutes).

Optional: if using, sprinkle 1/4 teaspoon xanthan gum into the caramel while stirring to help thicken and stabilize it. Add a pinch of salt here if you prefer the salt in the caramel instead of the crust (the recipe includes one pinch total).

Remove the caramel from heat and let it cool for 10–15 minutes so it thickens slightly but is still pourable.

Pour or spread the warmed caramel evenly over the cooled crust. Smooth the top with a spatula, then refrigerate the tray for 10 minutes to firm the caramel.

Melt the topping: place 1/2 cup sugar-free chocolate chips (100 g) or equivalent dark chocolate (85–90% cocoa) and 2 tablespoons coconut oil (27 g) in a heatproof bowl. Melt over a pan of simmering water (bain-marie) or in short bursts in the microwave, stirring until smooth.

Pour the melted chocolate mixture over the chilled caramel layer and spread evenly.

Chill the tray in the freezer for about 30 minutes, or until the chocolate is fully set.

Remove the tray from the freezer. Using the parchment overhang, lift the bars out of the tray and place on a cutting board. Grease or wet a sharp knife, then cut into bars. Return to the fridge or freezer to keep firm until serving.