How to Make It
Melt butter in a large skillet with a lid over medium-high until foaming. Add carrots, sugar, kosher salt, and thyme; cook, turning carrots with tongs to evenly coat in mixture, for about 1 minute. Add Campari and 2 tablespoons water; bring to a simmer and cook, partially covered, stirring once or twice, about 8 minutes.
Uncover and reduce heat to medium. Cook, tossing often with tongs, until carrots are tender when pierced with a fork and liquid is reduced to a glaze, 2 to 3 minutes. Top with flaky salt and several grinds of pepper.