Preheat oven to 350°F.
For the Streusel: In a mixing bowl, combine flour, sugar, nuts, cinnamon, and salt. Then stream in melted butter while mixing. Once crumbly, set aside.
For the Cake: In a mixing bowl, combine flour, salt, baking soda, and baking powder and set aside. In a separate bowl, combine yogurt and vanilla and set aside.
In a bowl of a stand mixer, mix softened butter and sugar until fluffy. Then add eggs, one by one, until combined. Next, add the flour mixture and yogurt mixture, alternating until combined. Pour batter into a greased 9 x 13 inch pan. Top with the prepared streusel and bake for 30-35 minutes or until a toothpick inserted comes out clean.
Remove from oven and sprinkle with Osmo's coffee salt if desired. Cool slightly and serve warm with coffee or beverage of choice. Enjoy!
