Preheat oven to 350 degrees. 9 inch baking pan – ungreased
In a large bowl, beat butter,sugar,egg and vanilla until light and fluffy.
Combine the flour,baking powder,salt, cinnamon and nutmeg in a medium bowl. Stir to combine. With the mixer on low speed add to the butter mixture. Beat until just combined. Stir in the oatmeal and 1/2 cup chocolate chips.
Spread the batter into the ungreased 9 inch baking pan. Sprinkle the top with the remaining chocolate chips. Bake 20 – 25 minutes or until set in the middle and toothpick inserted comes out clean.
