Combine the ½ cup (100g) of powdered sugar substitute and the ¼ cup (60 g) of butter in a medium-size saucepan over low-heat and stir until melted and the mixture has turned a light caramel color. Add the ½ cup (125g) of heavy (whipping) cream stirring constantly until it thickens (about 5 more minutes).

Add 2 cups of pecans (or any nut for variation) and stir to totally coat the nuts. Scoop a spoonful of the candy mixture onto the parchment paper covered sheet pan, evenly distributing the clusters on the sheet allowing for an inch or more between each cluster. Refrigerate the sheet pan for about 30 minutes until the clusters harden slightly.

For the chocolate-drizzle, combine chopped unsweetened dark chocolate (90% to 100% cacao) with 1 tablespoon of butter. Zap the mixture in the microwave for 30 to 60 seconds then stir thoroughly to combine the melted chocolate-mixture. A few more seconds in the microwave might be necessary to fully melt the chocolate. Once fully melted and slightly shiny, stir in 2 to 4 tablespoons of powdered sugar substitute (according to your personal taste).

Drizzle the chocolate over the pecan clusters and refrigerate for an additional 15 minutes or more. You can keep the clusters covered at room temperature or in the fridge according to you personal preferences.