Make streusel topping: Mix together flours, 3/4 cup brown sugar, 1 teaspoon cinnamon and 1 teaspoon salt. Cut in butter using a pastry cutter or fork until medium clumps. Mix in 1/4 cup hazelnuts. Refrigerate until ready to use.
Make streusel center: Mix together remaining 1/4 cup brown sugar, 1/4 teaspoon cinnamon and 1/2 cup hazelnuts
Make cake: Preheat oven to 350 degrees F. Spray non-stick cooking spray in a 9-inch tube pan with a removable bottom. Sift together the flour, baking powder, baking soda and salt in a medium bowl.
Using a stand mixer, beat together butter and usage until pale and fluffy, about 2 minutes. Beat in eggs, one at a time. Add vanilla and hazelnut extract.
Beat in flour mixture in 2 additional, alternating with yogurt and hazelnut creamer. Make sure to begin and end with the flour mixture. Beat until combined.
Spoon half the batter into prepared pan. Sprinkle streusel center mixture evenly over batter. Top with remaining batter. Use a offset spatula to spread over streusel center mixture.
Sprinkle streusel topping mixture on top of batter.
Bake 50-55 minutes, or until toothpick inserted in center comes out clean. Transfer pan to a wire rack and let cool completely. Remove cake from pan and place on wire rack.
Make glaze: Mix together powdered sugar and creamer. Drizzle over cake and let sit for 5 minutes before serving.