Blueberry Buckle (coffee cake)

(Recipe from Land O Lakes Treasury of Country Recipes, an awesome book with simple recipes which I picked up at a book fair for $7)

Cake:
2 cups flour
3/4 cup sugar
1/2 cup milk
1/4 cup butter, softened
1 egg
2 tsp baking powder
1/4 tsp salt (I reduced it from 1/2)
1/2 tsp nutmeg
1 cup fresh or frozen blueberries

Streusel Topping:
1/2 cup sugar
1/3 cup flour
1/2 tsp cinnamon
1/2 tsp nutmeg
1/4 cup butter, softened

Preheat oven to 375.
For the cake, combine all ingredients except blueberries untill well mixed. Fold blueberries into the batter. Spread into greased and floured 9" sq baking pan. (It will barely look like enough to cover the bottom).
For the topping, mix all the dry ingredients. Cut in butter till crumbly, sprinkle over batter.
Bake for 30-35 min.