Stuff: Clean mushrooms with a damp cloth. Pluck or cut the stems from the mushrooms so that they are fairly hollow. Chop up the stems and mix them with the cream cheese, cheddar, and jalapeno. Stuff the cheese mixture into each mushroom.
Bread & Bake: Preheat oven to 450 degrees F (232 C). Arrange 3 shallow bowls: 1 with flour, 1 with whisked egg, 1 with panko, salt, and pepper. Working in small batched, coat mushrooms in flour, then egg, then panko, setting finished mushrooms on a parchment paper-lined baking sheet. When all are finished, bake for 10 to 12 minutes, or until browned and crisp.
Buffalo: Dip each mushroom in buffalo sauce, then return to the oven for 5 minutes, until slightly dry.
Serve: Combine the dressing ingredients in a small bowl. Serve immediately with warm Buffalo Mushroom Poppers.
Notes
To keep your fingers from getting all gunky while breading, make 1 hand your “wet ingredients” hand and the other your “dry ingredients” hand. This will keep the breading from building up on your fingers as you work!