Initiate the process by preheating the oven to a temperature of 350ºF. Concurrently, position a baking rack atop a baking sheet that has been lined with foil. This will be set aside for later use.
Carefully extract the stems from the white button mushrooms.
In a mixing bowl, amalgamate the room temperature cream cheese, finely minced garlic, drained jalapeños, shredded cheddar cheese, and the prepared chopped bacon. Ensure the ingredients are combined to uniformity.
Using a spoon, methodically fill the caps of the mushrooms with the previously prepared cream cheese mixture. Subsequent to filling, position the mushroom caps onto the prearranged baking rack.
Commit the mushrooms to the oven and allow them to bake for a duration ranging from 15 to 20 minutes. Upon completion, they should exhibit a golden hue and the filling should be bubbling slightly. Ensure they are allowed to cool briefly prior to serving.