Start by making the pie shell. In a food processor, combine cake flour, all-purpose flour, and kosher salt. Pulse them together until they’re well mixed. Then, add chilled unsalted butter cubes and pulse again until the mixture looks like coarse meal.

With the processor running, drizzle ice water into the mixture until the dough just comes together. Then turn the dough out onto a work surface, gather any loose crumbs, and gently pat it into a disk. Wrapping it in plastic, refrigerate it for about an hour to chill it thoroughly.

After chilling, lightly flour the work surface and roll out the dough to a 14-inch round, about 1/4 inch thick. Carefully, ease the dough into a 9-inch round, 2-inch-deep cake pan, leaving the edges overhanging. Refrigerate it again for about 30 minutes to firm up.

While the crust chills, preheat the oven to 350°F. On a rimmed baking sheet, toss the thinly-sliced brussels sprouts with olive oil and roast them for roughly 20 minutes until they’re nicely browned and tender. After cooling, I coarsely chop them.

Lowering the oven temperature to 325°F, whisk together eggs, garlic powder, crushed red pepper flakes, onion powder, kosher salt, freshly ground black pepper, nutmeg, grated parmigiano reggiano cheese, crumbled goat cheese, and pure maple syrup. To this mixture, I add the roasted brussels sprouts and thinly sliced scallions.

Sprinkle some grated parmigiano reggiano cheese in the prepared pie shell, then pour the egg mixture over it. Placing the cake pan on a foil-lined baking sheet, bake the quiche for about 1 and a half hours, until it’s set.

Once baked, let the quiche cool on a rack for about 30 minutes. Trim any excess crust around the edges before cutting the quiche into wedges. This savory brussels sprout quiche is now ready to be served and enjoyed!