I’ve been gradually (granulatedly?) working through 15 pounds of brown sugar I overbought at Costco last year. The godsend foodstuff for brown sugar gluts is oatmeal cookies.
Finally worked them so they had crisp edges and melt into flat shapes. These aren’t soft, squishy oatmeal cookies. I don’t know how to make those.

1 ½ cups brown sugar
1 cup margarine
1 teaspoon vanilla
2 eggs (don’t have to be large)
1 cup white flour
1 ½ cups spelt flour (you can use whole wheat; I just happen to have a lot of spelt berries around these days)
1 teaspoon baking powder
2 cups uncooked oats (not the “quick” kind or any fancy kind; just the generic round tub of oats).

Beat the hell out of the brown sugar and margarine, until frothy. Add the vanilla and eggs and beat it more. Toss in the flours and baking soda—stir more gently this time. Finally, the oats. Don’t let them get soggy.

Heat the over to 350 degrees. Use that cooking spray stuff, or very lightly butter, a couple of cookie pans. (I use a cast iron pizza pan. I mention this because it has a heavy bottom and I don’t burn the cookies as easily when I use it.) Spoon teaspoonfuls of the batter onto the pan. (Use a spoon, not your fingers. You can thank me later.) Cook for about 10 minutes. I find it helps to switch the pan from the upper rack to the lower rack, or vice versa, midway through.
Eat, and rejoice that you’ve just used 1 ½ cups of brown sugar in one fell swoop.