Preheat the oven to 375℉. Line a baking sheet with parchment paper. Add ice to a large bowl of water.
In a skillet, cook bacon over medium-low heat 2 to 3 minutes per side, or until slightly cooked (not crispy). Transfer to a paper towel-lined plate.
Bring a large pot of water to a boil over medium heat. Add green beans and cook 4-5 minutes, or until tender-crisp. Transfer to ice water to stop cooking. Drain and dab beans dry with a paper towel.
Cut each slice of bacon in half (for a total of 12 slices). Gather 6 to 8 green beans and wrap bacon around the center (secure bacon with a toothpick for a tighter bundle) and place on the baking sheet. Repeat with remaining bacon slices.
Brush butter over the tops of the bundles and sprinkle evenly with brown sugar, salt and pepper.
Bake 20 to 25 minutes, or until bacon is crisp and beans are tender.
Notes
Air fry: Cook in the air fryer at 380°F for 11 to 13 minutes.Make-ahead: The bundles can be made in advance and refrigerated a day ahead of time. Wrap bundles and add butter and seasonings right before baking.