Preheat your oven to 350 F and line a baking sheet with parchment paper.
Beat the softened butter and granulated erythritol together until creamy. Add the egg and vanilla extract and mix well.
Stir in the almond flour, baking powder, and sea salt until a thick dough forms. Fold in the sugar-free white chocolate chips and chopped macadamia nuts.
Scoop rounded tablespoons of dough onto the prepared baking sheet, spacing about 2 inches apart. Flatten each one slightly.
Bake for 11 to 13 minutes until the edges are golden but the centers still look soft. Press a few extra white chocolate chips and macadamia pieces into the tops right out of the oven for a bakery-style look.
Let the cookies cool on the baking sheet for 10 minutes before transferring to a wire rack. They firm up beautifully as they cool.
