For the muffins: Preheat the oven to 375 degrees F. Spray a mini muffin tin with nonstick cooking spray.
Add the bacon to a medium skillet over medium heat and cook, stirring occasionally, until the bacon is crispy, about 5 minutes. Pour the bacon and fat into a bowl and let cool slightly.
Whisk together the cornmeal, flour, sugar, baking powder and salt in a large bowl. Add the buttermilk, oil and egg to the bowl with the bacon and whisk together. Stir the milk mixture into the dry mixture and pour the combined batter into the prepared mini muffin tin, filling just to the top of the cups. Bake until a toothpick inserted in the center comes out clean, 10 to 15 minutes.
For the orange butter: While the muffins are cooking, combine the butter, agave and zest in a medium bowl with a pinch of salt and stir until completely combined.