Prepare a grill for medium-high heat or turn on a gas burner.
Place the jalapenos directly on the grill or burner and cook, turning, until charred on all sides, about 10 minutes. Transfer to a resealable plastic bag and let steam for a few minutes. Use a paper towel to rub the skins off the peppers, then remove the stems and seeds and finely dice.
Mix the diced jalapenos, butter, lime juice, honey and garlic powder in a food processor or by hand until well blended. Season with salt and pepper. Spread a generous amount of jalapeno butter on each ear of corn, then wrap the corn in foil.
Place the corn on the grill or in a grill pan and cook on one side for 5 to 10 minutes. Flip and cook for another 5 to 10 minutes, until the kernels are bright yellow and you start to see grill marks.