Upside Down Rhubarb Muffins

1 cup finely chopped rhubarb (fresh or frozen)
½ cup brown sugar
¼ cup melted butter
1/3 cup butter, softened
1/3 cup sugar
1 egg
1 ½ cup flour
2 teaspoon baking powder
1 teaspoon nutmeg
½ teaspoon salt
½ cup milk

Preheat oven to 350 degrees . Grease 12 muffin cups.

Combine rhubarb, brown sugar, and ¼ cup melted butter in a small bowl and mix well. Divide mixture into each of the prepared muffin cups; set aside.

Beat together the 1/3 cup softened butter, sugar, and egg until fluffy; set aside.

Combine flour, baking powder, nutmeg, and salt and add to creamed mixture alternately with milk. Stir just to moisten. Spoon some of the batter on top of the rhubarb mixture in each muffin cup.

Bake at 350 degrees for 20 to 25 minutes. Place a cooling rack on top of pan and invert the pan with the rack. Leave pan over muffins for a few minutes so all the rhubarb runs out. Serve warm