Preheat oven to 350 degrees and grease & flour a 10" tube/bundt pan. I like to use Baker’s Joy, it has grease and flour in the spray and works like a dream.

In a small bowl combine the sugar, cinnamon and walnuts, set aside.

In a medium bowl whisk together the flour, baking powder, baking soda and salt.

In a large bowl, using a mixer, cream the butter and sugar at medium speed until fluffy 2-3 minutes.

Add the eggs, one at a time, beating until thoroughly mixed each time the eggs are added.

Add the dry ingredients alternately with the Greek yogurt with the vanilla extract to the creamed mixture, beating until combined with each addition.

Spread half the coffee cake batter in the prepared tube/bundt pan, spoon ⅔ of the cinnamon sugar topping over cake batter. Cover with remaining batter and top with remaining topping.

Bake for approximately 50-60 minutes or until inserted toothpick comes out clean or a few crumbs attached. (After 45-50 minutes if it is not done but is becoming too brown cover with foil and continue to bake.)