Combine peanut butter, egg, and sugar in a bowl. Mix well.

Divide the flour in half. Sift half of the flour and the baking powder into the mixture. Use a mixer to blend the mixture well. Then sift in the remaining flour.

After mixing the dough thoroughly, preheat the oven to 375°F (190°C) for 5 minutes. Shape the dough into small round balls and place them on a baking sheet. Press the balls down to flatten them slightly. You can add cashews, almonds, or walnuts on top of the cookies if desired.

Bake the cookies in the oven for 10 minutes. If they are not golden enough, you can bake them for a few more minutes.