Place flour, brown sugar, cinnamon, salt, and butter into a small bowl.
Using a fork, press ingredients together until butter is in small chunks. Use your fingers to pinch pieces together until streusel is mostly small crumbles. Some large crumbles are ok. Set aside.
In a medium size bowl, toss together the flour, cinnamon, baking powder, baking soda, and salt. Set aside.
In a large bowl with a handheld mixer or the bowl of a stand mixer fitted with the paddle attachment, cream the butter and sugars until light and fluffy. Add the eggs one at a time, beating on medium speed after each until combined. Add the vanilla and the yogurt and beat again on medium speed until completely incorporated.
Reduce mixer speed to medium-low and slowly add the dry ingredients. Increase mixer speed to medium and beat until no flour lumps remain. Do not over mix batter.
Sprinkle half (approximately 3/4 cup) of the streusel evenly into the bottom of your prepared bundt pan. Pour all of the cake batter into the pan and sprinkle the remaining streusel evenly on top of the cake batter. Bake for 42-45 minutes, or until a toothpick inserted in the center comes out mostly clean.
Remove from oven and allow to cool for 10 minutes on a wire cooling rack. Using oven mitts, carefully flip the coffee cake onto your serving dish/platter. To do this: flip the serving dish/platter over and place on top of the cooling bundt pan. Flip everything over and allow cake to cool completely in the pan, sitting on the serving dish. When cake is completely cool, lift pan off of the cake and cut to serve. Dust with powdered sugar if desired, keeping in mind the butter in the streusel that has been baked into the top of the cake will absorb the powdered sugar quickly. Leftovers can be kept covered tightly at room temperature up to 5 days or in the refrigerator up to one week. Cake freezes well, up to 2 months. Thaw in fridge overnight and allow to come to room temperature.
If using 9x13 baking pan, sprinkle about 1/4 cup of the streusel on the bottom of the sprayed pan. Layer batter in as normal, and sprinkle remaining streusel on top. Bake time is 28-30 minutes until golden brown or a toothpick inserted in center comes out clean. *It is always a good rule of thumb to use room temperature ingredients when using room temperature butter. To bring eggs to room temperature quickly, place in a bowl of warm water for 10 minutes.Recipe adapted from Ina Garten