chocolate peanut butter cake

INGREDIENTS

• 2 cups all-purpose flour
• 2 1/2 cups sugar
• 3/4 cup unsweetened cocoa powder, preferably Dutch process
• 2 teaspoons baking soda
• 1 teaspoon salt
• 1 cup neutral vegetable oil, such as canola, soybean or vegetable blend
• 1 cup sour cream
• 1 1/2 cups water
• 2 tablespoons distilled white vinegar
• 1 teaspoon vanilla extract
• 2 eggs
• 1/2 cup coarsely chopped peanut brittle (I skipped this)
• 10 ounces cream cheese, at room temperature
• 1 stick (4 ounces) unsalted butter, at room temperature
• 5 cups confectioners’ sugar, sifted
• 2/3 cup smooth peanut butter, preferably a commercial brand (because oil doesn’t separate out)
• 8 ounces semisweet chocolate, coarsely chopped
• 3 tablespoons smooth peanut butter
• 2 tablespoons light corn syrup
• 1/2 cup half-and-half