Set your smoker for 350 degrees F. We’re using the @NinjaKitchen Woodfire™ Outdoor Grill so we can use just 1/2 cup of pellets for this killer breakfast casserole.
Whisk together the eggs, 1 cup heavy cream, cinnamon, vanilla, and a pinch of salt in a large bowl. Add the challah slices and toss to coat in the custard. Lightly grease a casserole dish and layer in the soaked challah. Pour any leftover custard over the casserole. Smoke at 350 degrees F for 30 minutes. Meanwhile, make the maple bourbon syrup.
Add the bourbon to a small saucepan and reduce by half over medium high heat. Add the maple syrup and reduce again slightly. Set aside. Whip the remaining cup of heavy cream with the powdered sugar, a splash of vanilla extract and a pinch of salt until medium peaks form.
Serve the finished casserole by drizzling on the syrup, topping with big dollops of whipped cream, a sprinkle of maple sugar, and a hearty pinch of flaky salt.