Blueberry Coffeecake

A great recipe from my co-worker, Diane:

Ingredients
1/4 cup vegetable oil
1/2 c. oatmeal
1 tbs. butter
3/4 c. blueberry
1 egg
1/2 c. milk
1 1/2 c. all purpose flour
3/4 c. sugar
2 tsp. baking powder
1/2 tsp. salt
1/3 c. brown sugar
1 tbs. all purpose flour
1/2 tsp. ground cinnamon

Instructions
Preheat oven to 375.
Combine vegetable oil, egg, and milk. Sift together 1 1/2 c. flour, sugar, baking powder, and salt, and add them to the milk mixture. Mix well.
In another bowl, melt butter, add brown sugar, 1 tbsp. flour, cinnamon, and oatmeal.
Pour half of cake batter into a greased 9x9x2-inch pan. Spread blueberies evenly over batter. Add remaining cake batter. Top with the cinnamon oatmeal mixture.
Bake for 25 to 30 minutes.