Preheat the oven to 350ºF (177ºC).

Spray a 12-cup bundt pan with non-stick spray or use homemade cake release. Set aside.

Place flour, brown sugar, cinnamon, and salt into a small bowl. Toss together with a fork until combined.

Add the butter to the bowl, then use a fork to smash the pieces of butter into the mixture.

Use your fingers to press the ingredients together until butter is in small chunks.

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 or sour cream 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.

Pour approximately half of the coffee cake batter into the prepared bundt pan, then sprinkle half (approximately ¾ cup) of the streusel evenly onto the batter.

Pour the rest of the batter into the pan and sprinkle the remaining streusel evenly on top of the 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.

When cake is completely cool, lift pan off of the cake and cut to serve.