1 cup all-purpose flour
1/2 teaspoon baking powder
1/2 teaspoon baking soda
1/4 teaspoon salt
2 cups rolled (old-fashioned) oats
8 tablespoons (1 stick) unsalted butter, at room temperature
1/2 cup lightly packed light brown sugar
1/2 cup granulated sugar
1 large egg
1/2 teaspoon vanilla sugar
3/4 cup semisweet chocolate chips
Preheat the oven to 350 degrees F.
In bowl, stir the flour, baking powder, baking soda, salt, oats together with a whisk or fork.
In a large bowl, beat the butter, brown sugar, vanilla and granulated sugar together for 30 seconds until blended. Beat in the egg until smooth and barely fluffy. Add the flour-oatmeal mixture and the chocolate chips.
Drop walnut-sized balls of dough onto a nonstick or parchment-lined cookie sheet at 3-inch intervals. With moistened fingers, flatten and round out the cookies a little. Bake for 9 minutes. The cookies are done when they are lightly browned on top. Set the cookie sheets on a rack to cool.