Cook the corn – In a large skillet or Dutch oven, melt 3 tbsp butter over medium-high heat. Add the drained corn, 1 tsp salt, and ½ tsp black pepper. Sauté 7–8 minutes, stirring occasionally, until hot and lightly golden. Taste; add up to another ½ tsp salt if needed.
Mix the sauce – In a bowl, whisk together 1¼ cups mayonnaise and 1¼ cups sour cream.
Combine – Transfer the hot corn to a large bowl or foil pan. Stir in the mayo–sour cream mix until all kernels are coated.
Add toppings – Mix in 2 cups of the cotija cheese (reserve ½ cup for garnish). Squeeze in juice of 2 limes. Sprinkle in Tajín to taste. Stir well.
Finish & serve – Top with the remaining ½ cup cheese, more Tajín, and cilantro if using.