Mix the butter with the sugar until frothy, gradually stir in the eggs. Press the potatoes through the potato press or mash them with a fork, mix with the bitter almond oil and stir in. Mix the oatmeal with the flour and baking powder and stir into the batter.
Preheat the oven to 175 ° C. Grease a 22 cm springform pan and sprinkle with breadcrumbs. Pour the dough into the mold and smooth it out. Bake on the lowest rack in the oven for about 40 minutes.
Let the cake cool for a few minutes in the tin, then remove from the tin and place on a wire rack to cool completely. Sprinkle with powdered sugar to serve.