Preheat oven to 350°F. Line a baking sheet with 24 muffin liners. Add 2 to 3 pecan halves to each liner. (see recipe tips for muffin liners)
Melt butter in a saucepan over medium heat until it bubbles and turns light brown. Stir in powdered sweetener until smooth. Remove from heat once it starts to thicken.
Scoop the butter mixture into the muffin liners over the pecans, dividing it evenly.
Bake 10 to 12 minutes. You should smell a caramel scent when they’re ready.
Remove from oven. Add about 1 tablespoon white chocolate chips to each cluster. Let them soften for 30 to 60 seconds.
Use the back of a spoon to spread the melted chocolate over each cluster.
Sprinkle shredded unsweetened coconut on top while the chocolate is still warm.
Freeze the clusters on the baking sheet for about 1 hour until firm.
Notes
Don't overcook the butter mixture. If it gets too dark, it can turn gritty once cooled. Pull it as soon as it's bubbling and slightly thickened.
Use good-quality muffin liners or parchment-style liners. Thin paper liners can stick to the clusters once it hardens.