This isn't too far beyond the muffin but is a long time family favorite. The kids and I put this together many decades ago to show Mom/Dear wife that there was cornbread in the world besides the dinner fare she was used to growing up in the South. Now they make it for our grandkids.
BLUEBERRY CORNBREAD:
12 T (1 ½ sticks) Butter
1 C Turbinado sugar
3 Extra large eggs
1 ½ C Stone ground yellow cornmeal
2 C Unbleached white flour
1 T Baking powder
½ tsp Salt
2 C Whole milk
1 ½ C Wild Maine blueberries (or whatever)
Cream butter and sugar together in mixer. Add eggs until well blended. Add cornmeal. Sift flour, baking powder, and salt together, and add to mixer alternately with milk. Fold in blueberries by hand. Bake in large (10 inch), buttered, cast iron skillet at 375 degrees (F) for 45 minutes.