Marmalade Butterscotch Brownies

Position a rack in the center of the oven and heat the oven to 325 degrees F. Line the bottom and sides of a 9x13-inch straight-sided metal baking pan with heavy-duty aluminum foil, leaving about a 2-inch overhang on the short sides. Lightly butter the foil.

Put the butter in a large (4-quart) saucepan over medium-low heat and stir occasionally until melted, about 2 minutes. Off the heat, whisk in the cocoa powder until smooth, 1 minute. Add the sugar and salt, and whisk until well blended. Use your fingertip to check the temperature of the batter -- it should be warm, not hot. If it's hot, set the pan aside for a minute or two before continuing.

Whisk in the vanilla extract and then the eggs, two and then three at a time, until just blended. Sprinkle the flour over the batter and stir with a rubber spatula until just blended. Stir in the butterscotch chips.

Scrape the batter into the prepared pan and spread evenly. Drop the orange marmalade by tablespoons evenly over the top and, using a knife or small spatula, swirl into the batter. Bake until a toothpick inserted in the center comes out with small bits of brownie sticking to it, 35 to 45 minutes. Do not overbake. Cool the brownies completely in the pan on a rack, about 3 hours.

When the brownies are cool, use the foil overhang to lift them from the pan. Invert onto a cutting board and carefully peel away the foil. Flip again and cut into 24 squares. Serve immediately or wrap in plastic and store at room temperature for up to 3 days. They can also be frozen in an airtight container or freezer bag for up to 1 month.