- Grease a 9-inch cake pan and set aside. Preheat the oven to 375 degrees F.
To make the topping:
- In a medium bowl, combine rhubarb, ½ cup sugar and 2 teaspoons corn starch. Stir to combine and place in bottom of prepared cake pan.
- In a small bowl combine melted Kerrygold® salted butter and brown sugar and stir to combine. Drizzle over rhubarb mixture.
To make the cake:
- Place butter and sugar in another medium bowl and beat until combined. Add egg and vanilla and beat until thoroughly mixed.
- Add cinnamon, baking powder and ½ cup of the flour and beat until just combined. Add ¼ cup of the milk and beat until just combined.
- Add ½ cup of flour and beat until just combined. Add ¼ cup milk and mix. Add remaining 1/3 cup of flour and stir until just combined.
- Pour cake batter over rhubarb mixture and bake in preheated oven for 35-40 minutes or until toothpick comes out clean.
- Cool on rack for 15 minutes and then invert on serving platter. Serve warm with crème fraîche, if desired.