Melt the butter in a large pot or Dutch oven over medium heat. Add the chopped onion and cook until soft, about 5 minutes.
Add the minced garlic and jalapeño (if using). Cook for 1 minute until fragrant.
Pour in the vegetable broth and add the corn kernels. Bring the mixture to a simmer.
Cook for 10 minutes, allowing the flavors to combine.
Carefully transfer about half of the soup mixture to a blender. Add the milk. Blend until completely smooth and creamy.
Return the blended mixture to the pot. Stir in the heavy cream, chili powder, smoked paprika, and cumin.
Heat the soup gently over low heat until warmed through. Do not boil after adding the cream.
Taste the soup and season generously with salt and black pepper.
Ladle the soup into bowls. Top each serving with crumbled Cotija cheese, fresh cilantro, and a side of lime wedges. Serve immediately with tortilla strips for crunch.
Notes
For a healthier option, substitute the heavy cream with an equal amount of evaporated milk or use cashew cream for a vegan alternative.
If you want a deeper corn flavor, simmer the corn cobs in the broth for 15 minutes before removing them and adding the kernels.
This soup is excellent for meal prep; store leftovers in an airtight container in the refrigerator for up to 3 days.