Plum Upside Down Cake
I love buying beautiful seasonal fruit, and I often end up with more than I can simply eat on its own. Turning some of it into a cake is one of my favorite ways to enjoy it in a different form. This one is light and fruit-forward, and I like serving it with softly whipped vanilla cream.
Ingredients:
2 lb ripe plums, halved and pitted. More if needed to cover the bottom of a 9-inch cake pan
100 g granulated sugar, for the caramel
170 g unsalted butter, softened
225 g granulated sugar
4 large eggs, room temperature
1½ teaspoons vanilla extract
190 g all-purpose flour
1½ teaspoons baking powder
¼ teaspoon sea salt
Directions:
Prepare the pan: Heat the oven to 350°F. Butter a 9-inch solid cake pan. Halve and pit the plums.
Arrange the plums: Arrange the plums tightly in the bottom of the pan, overlapping them slightly as needed. You can arrange them casually or in a pattern, as long as the bottom is well covered.
Make the caramel: Combine 100 g sugar with ¼ cup water in a small saucepan(See Notes). Cook without stirring until the caramel reaches about 340°F / 171°C and is medium amber. Immediately drizzle the caramel evenly over the plums.
Make the batter: Whisk together the flour, baking powder, and salt. In a separate bowl, beat the butter and 225 g sugar until pale and fluffy, 3 to 5 minutes.
Add the eggs: Beat in the eggs one at a time, then add the vanilla.
Finish the batter: Add the dry ingredients and mix on low just until almost combined. Finish folding with a spatula.
Bake: Spread the batter over the plums and bake until golden and a tester comes out clean or with a few moist crumbs, about 1 hour or a little longer.
Invert: Let the cake rest briefly, for around 10 minutes. Then run a thin spatula or knife around the edge and invert onto a serving plate while the caramel is still warm.
Drizzling caramel over the plums.
Gently scrape the cake batter on top of the plums, smooth out the top.
Use a spatula or thin knife to gently loosen the sides of the cake if it is a bit stuck.
Serve with a side of vanilla whipped cream.
Notes:
Choose ripe but still firm plums. Very soft fruit tends to lose it shape during processing and can release too much juice.
I use a wet caramel here because the added water helps the sugar dissolve evenly and makes it a little easier to control. Swirl the pan gently as the sugar dissolves and the mixture heats. Once it begins to boil, avoid stirring and continue swirling the pan as needed for even caramelization. The caramel will set quickly once it hits the cake pan, so drizzle it over the bottom as evenly as possible rather than trying to spread it afterward.
