Melt 1Tbs butter in a skillet over medium high heat. Add carrots and cook until you get some nice brown marks on them - a couple of minutes.
Remove the carrots to a plate.
Add remaining butter, and when melted - add the brown sugar and stir until bubbling
Reduce heat, add carrots, salt and pepper and rosemary and cook covered (stirring) until carrots are cooked to your liking (took about 7 minutes).