In a medium mixing bowl, combine cream cheese, mayonnaise, sour cream, onion powder, garlic powder, and diced jalapenos. Use a hand mixer for quick blending.
Add 1 cup each of cheddar and jack cheeses and stir to combine.
In a large mixing bowl, toss together pasta, chicken, and most of the bacon (reserve about ½ cup to sprinkle over the top.)
Add the cream cheese mixture to the pasta mixture and stir gently until the mixture is evenly combined.
Spread filling into a 9x13 casserole dish.
Top with remaining cheeses. Sprinkle reserved bacon and fresh jalapeno slices over the cheese.
Bake for 20 minutes, until the cheese is melted.
Remove from oven and top with freshly sliced green onion. Serve hot.
Notes
Cook the pasta in boiling, salted water to season the pasta before it goes into the casserole. Use 1 tablespoon kosher salt per 4 quarts of water.
Using diced, pickled jalapenos is both extremely convenient and also infuses more of that delicious jalapeño flavor into the dish.
You can substitute 3 freshly diced jalapeno peppers for the jarred jalapeños - remove seeds and ribbing for a milder dish.
Popular pasta options include rotini (as we used here), bowtie, or penne. Wide egg noodles also work well, like in our family's favorite tuna noodle casserole.
Lower Carb Option: Omit the pasta and serve by itself or over cauliflower rice.
Store leftovers in an airtight container in the refrigerator for 2-3 days. To reheat, dish out your portion onto a microwave-safe dish and heat for 1-2 minutes.