Easy Brown Sugar Crumb Cake

Preheat the oven to 350 degrees F. Line a 9x9 baking dish with parchment paper. In a large mixing bowl, mix eggs, oil, milk, and vanilla together. In a medium bowl, combine flour, sugar, baking powder, and salt. Add the dry ingredients to the wet ingredients and mix well. Pour half of the batter into the prepared baking dish. In a small bowl, combine 1/2 cup packed light brown sugar, cinnamon, and 1 stick melted butter and mix well to create the glaze. Pour half of the brown sugar glaze on top of the batter, spreading it around. Top with the remaining cake batter. With a spatula, mix the glaze throughout the bottom and top layer of batter. Combine 1/2 cup flour, 1/3 cup brown sugar, and 1/2 stick melted butter together using a fork to create the crumble, and sprinkle it on top of the cake. Bake for 45-50 minutes. Serve warm. For optional icing, combine 1/2 cup powdered sugar and 3 tbsp milk in a small bowl and drizzle on top if desired. Enjoy!