- 2 tablespoons unsalted butter, melted, for brushing
- 12 ounces cream cheese (1½ 8-ounce blocks), at room temperature
- 1 tablespoon sour cream
- ¼ cup granulated sugar
- ¼ confectioners sugar
- 1 teaspoon pure vanilla extract
- 1 extra-large egg, at room temperature
- Pinch of salt
- 1 cup unbleached all purpose flour
- 3 tablespoons cake flour (not self-rising)
- 1 teaspoon baking powder
- ½ teaspoon salt
- 1 cup (2 sticks) unsalted butter
- 2 ounces unsweetened chocolate, chopped
- 6 ounces bittersweet chocolate, chopped
- 1 teaspoon instant espresso powder
- 2 teaspoons pure vanilla extract
- 1½ cups granulated sugar
- 3 generous tablespoons Lyles Golden Syrup or light corn syrup
- 3 extra-large eggs, at room temperature
- 1 extra-large egg yolk, at room temperature
- 1 cup semisweet chocolate chips
- Line a 13 × 9-inch baking dish with aluminum foil (dull side down for a glass dish, dull side up for metal), allowing a 2-inch overhang at each end. Brush the foil with melted butter and set the pan aside. If using a glass dish, preheat the oven to 325°F. If using a metal pan, preheat to 350°F.
- Make the cream cheese mixture. Using an electric mixer, beat the cream cheese with the sour cream, sugars, vanilla, egg, and salt until smooth. Set aside.
- Make the brownies. Whisk together and then sift both types of flour, baking powder, and salt. In a 2½-quart heavy-bottomed saucepan, melt the butter with the two types of chocolate over low heat. Remove the pan from the heat and stir in the espresso powder and vanilla. Whisk the sugar and syrup into the melted chocolate until smooth. Add the eggs and egg yolk, one at a time, whisking well after each addition. When smooth, add the dry ingredients. Using a batter-whisk, combine the mixtures until smooth. Fold in the chocolate chips using a large rubber spatula.
- Pour half the brownie batter into the prepared baking dish and gently spread it to each corner using a long icing spatula or a table knife. Drop heaping spoonfuls of half the cream cheese mixture, randomly, on top of the chocolate batter. Pour and lightly spread the remaining brownie mixture over the top. Drop spoonfuls of the remaining cheese mixture on top and swirl both mixtures together using either your index finger, the stem end of a thin wooden spoon, or a regular table knife, going through both mixtures until intertwined.
- Place the pan in the oven and bake the brownies until a toothpick inserted into the center comes out with some chocolate adhering to it without being overly wet, about 35 minutes. (If you shake the pan gently, the brownie cake will jiggle just a bit.) Avoid overbaking. P|ace the pan on a wire rack and let the brownie cake cool thoroughly. Once cool, cover the pan with aluminum foil and let it sit for at least 4 hours (preferably overnight) in the refrigerator.
- To cut the brownies, lift the brownie cake out of the pan using the overhang of foil as a handle, and invert it onto another flat tray lined with waxed paper. Peel off the foil, then re-invert, right side up, and discard the waxed paper. Slice the slab into 2-inch squares using a sharp knife. For easier slicing, wipe off the knife after each cut. To best preserve moistness, store sliced brownies in an airtight tin or in a heavy-duty rectangular plastic container, separated by sheets of waxed paper. Either way, because of the perishable cream cheese, store these brownies in the refrigerator. For best flavor, however, bring them to a cool room temperature before serving.