Italian Fresh Purple Grape Cake

Step 1
Preheat the oven to 350 degrees F (175 degrees C). Generously butter and flour a 9-inch springform pan, tapping out any excess flour.

Step 2
Beat sugar and eggs in the bowl of a stand mixer fitted with the whisk attachment until thick and lemon-colored, about 3 minutes. Add milk, olive oil, melted butter, and vanilla; mix until blended.

Step 3
Sift flour, baking powder, and salt into a large bowl. Add lemon zest and orange zest and toss until coated with flour.

Step 4
Spoon the flour mixture into wet ingredients; stir with a wooden spoon until thoroughly blended. Scrape down the sides of the bowl and mix once more. Let sit for 10 minutes to allow the flour to absorb the liquids.

Step 5
Add 7 to 8 ounces grapes to the batter; stir to incorporate. Spoon batter into the prepared cake pan and smooth out the top with a spatula. Set remaining grapes aside.

Step 6
Bake cake in the center of the preheated for 15 minutes. Remove from the oven and sprinkle reserved grapes over the top.

Step 7
Return to the oven and bake until the top is a deep golden brown and the cake feels quite firm when pressed with a fingertip, about 40 more minutes.

Step 8
Remove from the oven and cool on a wire rack for 10 minutes. Run a knife along the sides of the pan to loosen the cake. Release and remove the side of the springform pan, leaving the cake on the pan base. Let cool to room temperature. Cut thin wedges to serve.