Easy Cranberry Coffee Cake

Preheat the oven to 350°F. Grease an 8-inch square pan with butter.
To make the cake, combine the butter and white sugar in a large bowl. Beat with an electric mixer for approximately 3 minutes, or until light and fluffy. Add the eggs, lemon juice, and vanilla, and mix until just combined.
In a medium bowl, combine 1 cup of the flour and the baking powder.
Place the cranberries in a separate bowl and sprinkle with the remaining 1 tablespoon of flour, stirring gently to coat the berries. Add half of the dry ingredients to the wet ingredients and stir to combine. Add the sour cream, mix again, and add the remaining dry ingredients. Mix until just combined. Gently stir in the cranberries and pour the batter into the prepared pan.
To make the topping, place the flour and sugar in the same bowl that was holding the berries and add the melted butter. Stir lightly with a fork to combine. Sprinkle the sugary crumbs over the batter in the pan.
Bake for 42-46 minutes, or until a toothpick comes out clean or with moist crumbs. Let it cool completely before slicing.