Chocolate Chip Coffee Cake

Inspired by a little chat with my grandma today, I figured I'd make something I know she'd love.

Chocolate Chip Coffee Cake

Ingredients
Topping
1/4 cup brown sugar
1/4 cup granulated sugar
1 tablespoon (scant) cinnamon
1 cup semi-sweet chocolate chips

Cake
2 cups flour
1 tablespoon baking powder
1 teaspoon cinnamon
Generous pinch of salt
1 cup (2 sticks) butter softened
2 cups granulated sugar
2 cups non-fat plain yogurt
2 eggs
2 teaspoons vanilla
1/2 cup extra chocolate chips

Directions
1. Preheat the oven to 375 degrees
2. Grease a 9x13 inch baking dish
3. Make the topping - mix all topping ingredients in a small bowl and toss to combine
4. In a medium bowl, combine the flour, baking powder, 1 teaspoon cinnamon, and salt
5. In a large bowl, cream together the butter and sugar.  Mix in the yogurt, eggs, and vanilla
6. Using a rubber spatula, mix the dry ingredients into the wet until just combined
7. Pour half the batter into the prepared pan.  Spread to cover base of pan
8. Sprinkle half the topping over the batter
9. Pour in the rest of the batter.  Spread evenly.  Pour the remaining topping over the batter
10. Sprinkle on the additional chocolate chips
11. Bake for 30 - 35 minutes or until top is golden brown and tester inserted into center of cake comes out clean.  Cool completely on rack