Put the oatmeal in a bowl and mix well with the yogurt.
Add whole wheat flour, baking powder, and salt, mixing evenly.
Add cold butter and quickly mix by hand until well distributed.
Gather the dough and shape it into a 2~3cm thick round or triangle, then cut.
Place parchment paper on a baking pan and put the dough pieces on top.
Bake in a preheated oven at 180°C for 20-25 minutes until done.