https://neighborfoodblog.com/rhubarb-upside-down-cake/


2 Tablespoons butter (melted)
1 1/2 cups granulated sugar (divided)
1/4 cup brown sugar
2 cups chopped rhubarb
1 1/2 cups flour
2 teaspoons baking powder
3/4 teaspoon salt
6 Tablespoons butter (at room temperature)
2/3 cup milk
1 teaspoon vanilla
Zest of 1 lemon
1 egg


INSTRUCTIONS
1. Preheat the oven to 350 degrees. Grease a 9 or 8 inch round cake 
	pan with butter.
2.Combine the melted butter, 1/2 cup granulated sugar, brown sugar, 
	and the rhubarb in a bowl, then spread the mixture onto the 
	bottom of the cake pan.
3. Sift flour, remaining 1 cup sugar, baking powder, and salt together 
	in a medium mixing bowl. Add the butter in tablespoon sized 
	chunks , milk, vanilla, and lemon zest. Beat on medium high 
	speed for 2 minutes. Add the egg and beat an additional 2 minutes. 
	There may still be small lumps of butter, the size of a pea 
	or smaller, in the batter.
4. Pour the batter over the rhubarb. Bake until toothpick inserted 
	in the center comes out clean, about 45-50 minutes. If you're 
	baking in a 9 inch pan, begin checking at 40 minutes. If the 
	cake is looking too brown at the 35 minute mark, cover it 
	with a sheet of foil.
5. Allow the cake to cool for about 5 minutes then loosen the sides 
	by running a knife around the edges. Place your cake plate 
	on top of the pan then use your hands to sandwich them together 
	and flip the pan over onto the cake plate. Carefully lift the 
	cake pan off the cake and allow the topping to run over the 
	sides. Serve warm with ice cream.