Pre-heat oven to 350° (180° celsius), grease & flour a 10" (4 liter) tube/bundt pan.
FOR THE TOPPING
In a small bowl combine the sugar, cinnamon and walnuts.
FOR THE CAKE
In a medium bowl whisk together the flour, baking powder, baking soda and salt.
In a large bowl cream the butter and sugar at medium speed until fluffy 2-3 minutes, add the eggs, one at a time, beating until light and creamy, 2 minutes.
Add the dry ingredients alternately with the greek yogurt and vanilla to the creamed mixture, beat until smooth.
Spread half the batter in the prepared tube/bundt pan, spoon ⅔ of the topping over 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. Cool in the pan, then remove to a clean plate. Enjoy!
Notes
To roast the nuts, place them in a single layer on an ungreased baking / cookie sheet. Bake 5 to 8 minutes in a pre-heated 350F (180C) oven or until they are golden brown, remove immediately from pan to cool. Then coarsely chop.With cakes and other baking, it’s always better to use room temperature ingredients. So, take any cold ingredients out of the refrigerator an hour ahead of time or sooner if it’s cool in your kitchen. Room temperature ingredients blend easier, creating a silky batter, which will help to create a light tender baked good.Instead of greek yogurt you could substitute with regular yogurt or sour cream both with a 1-1 substitution.As long as the cake is unfrosted it should be kept at room temperature. Keep it in a cake container or well wrapped. It will keep for up to 3 days. If you store it in the fridge, wrap tightly to keep it from drying out. It will keep for up to 5-6 days in the fridge.To freeze the cake, be sure to cool it completely then wrap it tightly in either plastic wrap or foil, place it in a freeze safe bag. The cake will keep for up to 2 months. When ready to thaw place the wrapped cake in the refrigerator to thaw before serving.