Cook’s Illustrated magazine has a recipe for “family style” creme brulee cooked in an 11 by 17 pan. It serves 8. I have made it before and it comes out perfectly. If you made a 2 3/4 recipe, you could fill two 11 by 7 pans and 6 cupstard cups, and that would serve 22. The custard cups only take 25-35 minutes, so be sure to check them earlier. They should be 170F, just like the large custard.
4 cups heavy cream, chilled
2/3 cup granulated sugar
pinch table salt
1 vanilla bean halved lengthwise
12 large egg yolks
8 - 12 teaspoons turbinado sugar or Demerara sugar
1. Adjust oven rack to lower-middle position and heat oven to 300 degrees.
2. Combine 2 cups cream, sugar, and salt in medium saucepan; with paring knife, scrape seeds from vanilla bean into pan, submerge pod in cream, and bring mixture to boil over medium heat, stirring occasionally to ensure that sugar dissolves. Take pan off heat and let steep 15 minutes to infuse flavors.
3. Meanwhile, place 1 1/2-quart casserole or 11 by 7-inch baking dish in larger baking dish or roasting pan. Bring kettle or large saucepan of water to boil over high heat.
4. After cream has steeped, stir in remaining 2 cups cream to cool down mixture. Whisk yolks in large bowl until broken up and combined. Whisk about 1 cup cream mixture into yolks until loosened and combined; repeat with another 1 cup cream. Add remaining cream and whisk until evenly colored and thoroughly combined. Strain through fine-mesh strainer into 2-quart measuring cup or pitcher (or clean medium bowl); discard solids in strainer. Pour mixture into empty casserole or baking dish. Custard should reach about two-thirds of way up dish, with depth of 1 to 1 1/4 inches.
5. Carefully move pan holding baking dish on oven rack; pour boiling water into larger pan, taking care not to splash water into ramekins, until water reaches two-thirds way up custard-filled dish. Bake until center of custard is just barely set and no longer sloshy and digital instant-read thermometer inserted in center registers 170 to 175 degrees, 40 to 50 minutes. Begin checking temperature about 5 minutes before recommended time.
6. Transfer dish with custard to wire rack; cool to room temperature, 2 1/2 to 3 hours. Set custard on rimmed baking sheet, cover tightly with plastic wrap, and refrigerate until cold, at least 4 hours or up to 4 days.
7. Uncover custard; if condensation has collected on custard, place paper towel on surface to soak up moisture. Sprinkle with turbinado sugar; tilting and tapping for even coverage. Ignite torch and caramelize sugar. Refrigerate cr?me brulee, uncovered, to re-chill, 30 to 45 minutes (but no longer); serve.