Ingredients:

  • 1 cup all-purpose flour
  • 1/2 cup brown sugar, packed
  • 1 tbsp ground cinnamon
  • 6 tbsp unsalted butter, cold & cubed
  • 1/4 tsp salt
  • 2 cups all-purpose flour
  • 1 cup granulated sugar
  • 2 tsp baking powder
  • 1/2 tsp salt
  • 1 cup plain full-fat Greek yogurt
  • 1/2 cup unsalted butter, melted & cooled
  • 2 large eggs, room temperature
  • 2 tsp vanilla extract

Instructions:

  1. In a small bowl, whisk together 1 cup flour, brown sugar, cinnamon, and 1/4 tsp salt.
  2. Use a pastry cutter or fork to work the cold cubed butter into the streusel mixture until it resembles coarse wet sand with pea-sized lumps.
  3. Place the streusel in the refrigerator to chill while preparing the batter.
  4. In a large bowl, whisk together melted butter and granulated sugar. Add eggs one at a time, then stir in Greek yogurt and vanilla extract until smooth.
  5. Sift 2 cups flour, baking powder, and 1/2 tsp salt into the wet ingredients. Gently fold with a spatula until just combined.
  6. Pour half the batter into a parchment-lined 9x9 inch square pan. Sprinkle half of the chilled streusel over the batter, then cover with the remaining batter.
  7. Spread the remaining streusel evenly across the top and press lightly.
  8. Bake in a preheated oven at 350°F (175°C) for 30–35 minutes, or until a toothpick inserted into the center comes out with a few moist crumbs.
  9. Allow the cake to cool in the pan for at least 30 minutes before slicing.