Preheat the oven to 340°F (170°C), and line a sheet pan with parchment paper.

In a large bowl, beat the butter with powdered sugar, lemon zest, and almond flour until light and creamy. Add the egg and mix until fully incorporated. Sift in the all-purpose flour and baking powder, stirring just until the dough comes together. Fold in the white chocolate and toasted pecans.

Scoop tablespoon-sized portions of dough, roll into balls, and gently flatten onto the prepared baking sheet.

Bake for 12 minutes, or until the edges turn lightly golden.

Allow the cookies to cool completely on a wire rack before serving.