Preheat oven to 350 degrees. Generously butter 2 9-in round pans.
Topping - In a small bowl combine the topping ingredients. Work in butter with a fork, pastry cutter or your clean fingers. It should resemble course crumbs.
Cake - Whisk the dry ingredients in a large bowl. In a separate bowl, whisk the eggs, sugars, yogurt and butter.
Make a well in the center of the dry ingredients and add wet ingredients. Mix gently, do not over mix. Batter will be on the thick side.
Pour into pans and smooth tops with a spatula. Sprinkle the tops with the cinnamon topping.
Bake for 20-30 minutes rotating halfway through. Check the center with a toothpick. Do not over cook or it will dry out.
Glaze - Mix the powdered sugar and cinnamon in a small bowl. Add milk until you reach desired consistency. Drizzle over cake when cool. Don't put too much as this is a very sweet cake already!