
Preheat oven to 350
Cream together the butter and sugar. Add the eggs, vanilla and almond and beat until it is well combined. You can use a stand mixer but I found that a hand held worked just fine for this recipe!
Add the flour, baking powder, baking soda, and salt and mix until just combined. Then add the cup of sour cream and mix to combine but be careful not to over mix. Fold in the chopped rhubarb.
Spray a glass 9x13 and pour and spread your batter into the dish. Set aside while you make the topping.
For the topping: In a small bowl combine the brown sugar, 1/4 cup flour, and cinnamon. Once mixed together, use a pastry blender (or your fingers) and cut in the cold butter. Sprinkle this mixture onto your coffee cake batter. Sprinkle with the slivered almonds.
Bake at 350 for 40-45 minutes until golden brown and a cake tester comes out clean. Serve warm with whipped cream or chill to slice into perfect little bars.