Preheat oven to 350°. Scrub outside of beets, then wrap each beet in aluminum foil. Place foil-wrapped beets on a baking sheet, and bake in preheated oven for 50-60 minutes, or until the beets are soft when pierced with a fork.
Remove beets from oven and let cool until cool enough to handle—about 15 minutes. Meanwhile, heat the vinegar, honey or maple syrup, salt and pepper in a small saucepan over medium-high heat. Bring to a boil, reduce heat and simmer until thick and bubbly—about 3 minutes.
Using clean hands, rub off the peels of the beets, or alternatively, use a sharp vegetable peeler to peel off the peels. Slice the peeled beets into 1/4″ rounds. Layer rounds on a platter, then drizzle with the glaze before serving. Season with additional salt and pepper, if desired.