Preheat oven to 350℉ and adjust baking rack to lower third of oven. Grease a 10 cup bundt cake pan, or spray with non stick spray.
In a food processor, pulse together streusel ingredients until resembles small pebbles, about 8-10 times. Sprinkle ⅓ of the mixture along the bottom of the pan and set the rest aside.
Whisk together eggs, yogurt and vanilla in a bowl (I like to do it right in the 2 cup measuring cup so there is one less bowl to wash).
In a large mixing bowl, combine dry ingredients for about 30 seconds.
Add butter and mix for a few minutes until it resembles wet sand with bits of butter.
Add egg yogurt mixture, half at a time, and beat until light and fluffy scraping sides down a few times.
Pour half of the cake batter to the bundt pan. Sprinkle half of the remaining streusel over the top. Repeat with remaining cake batter and streusel.
Bake until cake is firm to the touch and a skewer inserted in the center comes out clean, about 50 minutes.
Let cool on a cooling rack for 30 minutes in the pan. Then invert on to a serving plate. Let cool to room temperature before serving.