Roast the jalapeños. Preheat the broiler to high. Place 1 or 2 whole jalapeños on a small sheet pan. Broil for 3-5 minutes, rotating the peppers 2-3 times, until charred all over. Let cool, then thinly slice/chop. Set aside until serving.Mix the spices. In a bowl, combine the chili powder, paprika, cayenne, and a pinch of salt.Heat the olive oil in a skillet over medium-high heat. Add the onion and cook until soft, 5 minutes. Add the poblano pepper, 1-2 chopped jalapeños (seeded if desired), garlic, 1 teaspoon of the spice mix, and season with salt and pepper. Cook until the peppers are softened, 5 minutes.Reduce the heat to low. Mix in the cream cheese until melted and creamy. Stir in the sour cream. Cook until warmed throughout. If desired, thin the dip with milk.In a separate skillet, melt the butter until golden. Mix in 3 teaspoons of the spice mix, plus a pinch of chili flakes and salt. Cook another minute, then remove from the heat.Mix the mayo and lime juice with a pinch of salt. Spoon the dip into a bowl. Top with roasted jalapeños and drizzle the mayo and spicy butter over the peppers. Sprinkle with cheese and cilantro. Serve with chips for scooping!