Preheat oven: Set to 180 °C / 350 °F and grease a round or square baking pan (8- or 9-inch). Prepare the cherry filling: In a small saucepan
combine cherries
sugar
cornstarch
and lemon juice. Cook over medium heat until thickened (about 5 minutes). Let cool. Make the cake batter: In a large bowl
beat butter and sugar until light and fluffy. Add eggs one at a time
mixing well. Stir in sour cream and vanilla. In another bowl
whisk flour
baking powder
baking soda
and salt. Combine dry and wet ingredients; mix until smooth. Assemble: Spread half the batter into the pan. Spoon the cherry mixture over it
then top with the remaining batter (it’s fine if some cherries show through). Make the crumble topping: Combine flour
brown sugar
butter
and cinnamon. Rub with fingers until crumbly. Sprinkle evenly over the batter. Bake: Bake for 35–40 minutes
until golden brown and a toothpick comes out clean. Let cool before slicing. Serve: Delicious warm or at room temperature — perfect with coffee or tea.