Brush the boiled corn with mayonnaise and season with kosher salt and pepper. Place on the heated grill and cook 5-6 minutes each side, or until golden and slightly charred. Remove from heat and allow to cool for 5-10 minutes before cutting off the kernels. Add to a large mixing bowl and set aside.
Brush the pineapple spears with oil and place on the grill. Cook until golden and lightly charred, 6-8 minutes per side. Cut into 1/2’’ pieces and add to the corn.
Add the lime zest, 3/4 cup of the cilantro, jalapeño, and 3/4 cup of cotija, cherry tomatoes, and mix until combined. Pour over the lime juice and toss once more—taste for additional lime or salt. Garnish with the remaining cilantro, cotija, and chili powder.
Serve warm or chilled with grilled meat, chips, or fish.