Preheat the oven to 180°C (356°F).
In a bowl, mix whole wheat flour, baking powder, and salt.
Cut cold butter into small pieces and mix in with your hands or a scraper until crumbly.
Add milk and egg, and mix until the dough comes together.
Roll out the dough to 2~3cm thickness and cut into your desired size.
Transfer to a baking pan and bake for 15-20 minutes until golden brown.