Preheat the oven to 180°C (356°F).
Combine whole wheat flour, baking powder, and salt in a bowl.
Cut cold unsalted butter into small pieces and mix in with your fingertips until crumbly.
Add milk and erythritol, mixing until the dough comes together.
Flatten the dough to a thickness of 2cm, then cut into triangles or circles.
Place on a baking sheet lined with baking paper.
Bake in the oven at 180°C (356°F) for 18-20 minutes.