Aunt Anne's Coffee Cake

Step 1
Preheat the oven to 350 degrees F (175 degrees C). Grease and flour a 9×13-inch pan.

Step 2
Make streusel topping: Combine sugar, flour, and cinnamon in a medium bowl. Cut in butter until mixture resembles coarse crumbs. Set aside.

Step 3
Make cake: Combine flour, sugar, baking powder, and salt in a large bowl. Cut in butter until mixture resembles coarse crumbs. Whisk together egg and milk in a separate bowl; stir in vanilla.

Step 4
Pour egg mixture into crumb mixture; mix until just moistened.

Step 5
Spread into the prepared pan and sprinkle with streusel topping.

Step 6
Bake in the preheated oven until a toothpick inserted into the center of the cake comes out clean, 25 to 30 minutes.

Step 7
Allow to cool before slicing.