Whole wheat buttermilk cornbread

Adapted from Grandmother's Buttermilk Cornbread from allrecipes.com

1/2 cup butter
1/2 cup brown sugar
2 eggs
1 cup buttermilk
1/2 teaspoon baking soda
1/2 teaspoon salt
1 cup cornmeal
1 cup whole wheat flour
1 cup corn (frozen)

1) Preheat oven to 375F
2) Melt butter in a cast-iron skillet. As soon as butter is melted, add the sugar and beat in eggs. Mix in buttermilk, salt and baking soda. Slowly mix in flour and cornmeal until no lumps remain. Fold in corn.
3) Place skillet into oven, bake for 30 minutes, or until fork comes out clean.