Concord Grape Cake

Ingredients

• For the cake:
• 3 tablespoons unsalted butter, melted
• 2 large eggs, at room temperature
• 1/2 cup packed light brown sugar
• 1/2 teaspoon salt
• 1/3 cup sweet white wine, at room temperature
• 1/3 cup milk, at room temperature
• 3/4 cup vegetable oil
• Finely grated zest of 1 lemon
• 1 1/2 cups all-purpose flour
• 1 tablespoon baking powder
• 12 ounces Concord grapes, split in half, seeds removed
• For the concord grape jam:
• 1 pound Concord grapes
• 1 cup sugar
• 1 tablespoon lemon juice

Directions

1. For the cake, set a rack in the middle of the oven and heat it to 375 degrees F. Use 1 tablespoon butter to butter a 9-inch round cake pan. Fit parchment into the bottom, then use whatever butter is still on the pastry brush to grease it again.
2. Beat the eggs and brown sugar on medium-high speed until the mixture turns pale yellow and foamy, about 2 minutes. Add the salt, wine, milk, oil, and lemon zest, and beat until everything comes together, about 1 minute.
3. Stir the flour and baking powder together in a small bowl. Turn the mixer down to low and add the flour mixture. Mix only until the batter comes together, scraping the sides and bottom of the bowl with a rubber spatula as needed. Fold in the grapes.
4. Scrape the batter into the prepared pan. Bake for 25 to 30 minutes, turning the pan at the halfway point, until a cake tester poked into the center comes out clean.
5. Let the cake rest in the pan about 10 minutes, then flip it onto a large plate. Right away, flip it again onto a cooling rack set over a parchment-lined baking sheet to catch any drips.
6. For the Concord grape jam, as the cake cools, tuck a small plate into the freezer.
7. Pinch the grapes to slip off the skins, and put the skins in a food processor. Add 1/4 cup sugar and pulse until the skins are completely pureed.
8. Combine the pureed skins, peeled grapes, lemon juice, and the remaining 3/4 cup sugar in a medium heavy-bottomed saucepan. Bring the mixture to a boil over medium-high heat, then reduce the heat to medium-low and simmer, stirring frequently, until it has thickened and reduced to 1 cup, 25 to 30 minutes.
9. Strain the hot jam into a glass measuring cup and discard the seeds; the strained jam will measure about 3/4 cup. To check doneness, drop a tablespoon of jam onto the chilled plate and leave it for 1 minute. Tilt the plate: if the jam runs, pour it back into the saucepan, simmer 3 to 5 minutes, and test it again. The jam is ready when it stays in a mound.
10. Smooth the warm jam over the warm cake, then let it cool completely, about 1 hour. Serve.