Place a rimmed baking sheet on bottom rack of oven. Preheat to 450°F.
Toss brussels sprouts in oil in a large bowl and season with salt and black pepper.
Remove baking sheet from oven. Grab a pair of tongs and arrange brussels cut-side down on baking sheet. Roast on bottom rack until softened and deeply browned (about 20 to 25 minutes).
While the brussels sprouts are roasting, bring honey to a simmer in a small saucepan over medium-high heat. Reduce heat to medium-low and cook, stirring often, until honey is a deep amber color and foamy (about 3 to 4 minutes). Make sure you don’t burn it.
Remove honey from heat and add vinegar, Crystal Hot Sauce, and red pepper flakes. (Expect it to bubble up when you add the vinegar.) Whisk until the sauce is smooth, then return to the saucepan to medium heat.
Add butter and salt. Cook, whisking constantly, until glaze is glossy, bubbling, and slightly thickened (3 to 4 minutes).
Transfer brussels sprouts to a large bowl. Add glaze and scallions and toss. Transfer to a platter. Top with the grated lemon zest.