Preheat Oven and Prepare Baking Sheet: Begin by preheating your oven to 350 degrees Fahrenheit. Meanwhile, arrange a baking rack on a foil-lined baking sheet and set it aside for later use.

Prepare Mushrooms: Carefully remove the stems from the white button mushrooms, creating a cavity for the filling.

Mix Filling: In a bowl, combine the room-temperature cream cheese, finely minced garlic, drained jalapeños, shredded cheddar cheese, and the prepared chopped bacon. Mix these ingredients until they are uniformly combined.

Fill Mushrooms: With a spoon, meticulously fill the caps of the mushrooms with the cream cheese mixture prepared earlier. Once filled, place the mushroom caps on the previously prepared baking rack.

Bake Mushrooms: Place the mushrooms in the preheated oven and bake them for 15 to 20 minutes. The mushrooms should be golden in color with the filling bubbling slightly upon completion. Allow them to cool for a short period before serving.