Preheat oven to 350°F. Grease a 9-inch x 13-inch pan.
In a medium bowl, stir together the brown sugar, granulated sugar, salt and cinnamon. Add the melted butter and stir until well combined. Using a fork, mix in the flour until well combined and crumbs form.
Mix together the flour, baking powder, baking soda and salt in a medium size bowl until well combined, set aside.
Using an electric mixer, cream the butter until smooth. Slowly add in the sugar and beat until fluffy. Incorporate the eggs and scrape down the sides of the bowl. Add the yogurt and vanilla and beat until just combined. Slowly add in the dry ingredients and beat until fully combined.
Pour the batter into the prepared pan and top with large chunks of the crumb mixture.
Bake for 45-50 minutes, until a fork inserted into the middle comes out clean.