• Preheat oven to 350°F. Grease a 9×13-inch baking dish.

  In a medium bowl, mix the brown sugar, cinnamon, flour, and melted butter until crumbly. Set aside.

  In a separate bowl, whisk together the flour, baking powder, baking soda, and salt.

  In a large bowl, cream the softened butter and sugar until light and fluffy.

  Add eggs one at a time, mixing well after each addition. Stir in vanilla.

  Mix in the sour cream and applesauce until smooth.

  Gradually add the dry ingredients and mix just until combined.

  Spread half the batter into the prepared pan. Sprinkle with half the topping.

  Add remaining batter and finish with the rest of the topping.

  Bake for 55-60 minutes, or until a toothpick inserted in the center comes out clean.

  Cool slightly before serving.

Notes

• Do not overmix once the flour is added—this keeps the cake tender.

  Applesauce adds moisture without making the cake dense.

  Store covered at room temperature for up to 2 days or refrigerate for longer storage.