01 -
Heat the oven to 350°F and grease a solid 9-inch round cake pan.
02 -
Pour the two tablespoons of melted butter into its base. Sprinkle brown sugar evenly over the butter.
03 -
Arrange measured strawberries and chopped rhubarb stalks over the sugar.
04 -
Cream the separate softened butter with white sugar until evenly lighter. Beat in egg and vanilla.
05 -
Whisk flour, baking powder, baking soda and salt separately.
06 -
Add that mixture to the creamed mixture alternately with buttermilk, stirring just until combined. Spoon and gently spread batter over the fruit.
07 -
Bake about thirty to thirty-five minutes, continuing until a tester in the cake shows no wet batter.
08 -
Rest five minutes, loosen the edge and carefully invert onto a sturdy plate using oven mitts. Let cool before serving with optional whipped cream.