Heat the oven to 400ºF. Coat a 12-cup muffin pan with cooking spray.
Combine the cranberries and orange juice in a microwaveable bowl or small saucepan. Heat the mixture on high power in the microwave or over high heat on the stovetop just until it simmers, 3 to 4 minutes. Remove the pan from the heat and let the cranberries stand until they are plump, about 10 minutes.
In a large bowl, whisk together the eggs, buttermilk, oil, brown sugar, salt, cranberry mixture, and chipotle peppers. Scatter the baking powder over the top and whisk until blended. Gently stir in the cornmeal and flour until the batter is almost free of lumps.
Fill the muffin cups two-thirds full and bake until a knife inserted in the center of a muffin comes out clean, 12 to 15 minutes. Cool the muffins in the pan on a rack for 5 minutes. Then turn them out onto the rack to cool until warm. Serve warm or completely cooled.
Tip: Cut the muffins in half and serve with a drizzle of honey for extra sweetness.