Cream the butter until creamy. Add granulated sugar and mix together.
Add a beaten egg little by little, and mix. (Add in 5 portions.)
Add sifted flour and baking powder, and fold in with a spatula.
Roll the dough into a ball until it's no longer floury.
Roll out the dough to a 5 mm thickness, and cut out shapes with cookie cutters. Bake in the oven for 20-25 minutes at 170℃ / 340℉.
When the cookies are lightly browned, they're done.
Story Behind this Recipe
I rearranged a cookie recipe, which I had made for the first time when I was in elementary school. I made the cookies low calorie. Bake the cookies on a 30 x 30 cm baking sheet twice. You'll have a lot of cookies.
The dough is very crumbly and floury at the beginning during Step 3, but if you keep mixing, it will look like the picture in Step 4.