Preheat oven to 350º. In a large nonstick skillet over medium heat, cook bacon in batches until crispy, about 8 minutes. Drain on a paper towel–lined plate, then chop.

In a large bowl, mix cream cheese, mayo, sour cream, garlic powder, most of the cooked bacon (reserve some for topping), most of the jalapeños (reserve some for topping), and 1 c. cheddar and 1 c. Monterey Jack; season with salt and pepper.

Transfer to a small ovenproof skillet or baking dish. Sprinkle with remaining ½ cup c. cheddar and ½ c. Monterey Jack and reserved bacon and jalapeños.

Bake dip until golden and bubbly, 15 to 20 minutes. (If desired, broil 3 minutes to get cheese extra-golden.)

Transfer mixture into a 1-qt. baking dish that will fit in your Instant Pot. Cover dish with foil.

Place the trivet in bottom of pot and pour in 1 c. water. Fold a large piece of foil (about 18") into thirds to make a long “sling” and lower into pot. Place baking dish on trivet, centered on the foil strip. Fold strips over top, but not touching the top. Lock lid and set to Pressure Cook on high for 15 minutes.

Follow manufacturer’s guide for quick release, making sure to wait until cycle is complete before unlocking and removing lid. Using foil strips and pot holders, carefully remove baking dish.

Turn on broiler. Sprinkle top of dip with remaining ½ c. cheddar and ½ c. Monterey Jack. Broil, watching closely, until cheese is bubbly and golden, about 3 minutes.

Top with reserved bacon and jalapeños.