Preheat oven to 350°F/180°C. Lightly grease the cups of a 12-c. muffin pan.
Preheat a 10-in. omelette or fry pan till the rim of the pan is hot to the touch. Add the bacon and cook until crisp, turning once. Drain the bacon on paper towels and dice when the bacon has cooled.
Combine the bacon, 1/2 c. cheese and jalapeno pepper in a small bowl and set aside.
Combine the butter and milk in a 1-qt. sauce pan and heat over low heat until the butter has melted. Remove from the heat.
In a small bowl, whisk the eggs lightly. In a separate larger bowl, sift the flour, baking powder, sugar and salt. Stir in the cornmeal.
Create a well in the center of the dry ingredients. Pour the eggs and milk mixture into the well.
Using a fork, combine the wet and dry ingredients until just incorporated. Fold in the bacon, cheese and jalapeno pepper.
Divide the batter evenly among the cups. Batter should fill the cups half-way. Sprinkle remaining 1/4 c. cheese over the tops.
Bake until muffins are golden brown, about 20 minutes. Allow to cool before serving.