Preheat the Blackstone to medium-high (375–400°F). Oil lightly and char the corn in a single layer, 2–3 minutes, tossing once, until blistered. Remove to cool. (Skip if using leftover grilled corn.)
In a large bowl, whisk flour, cornmeal, baking powder, chili powder, Tajín, garlic, salt, and pepper. Stir in eggs, milk, lime juice, and zest to form a thick batter.
Fold in the charred corn, cotija, and cilantro. Adjust to a scoopable consistency with a little flour or milk.
Stir all dipping-sauce ingredients together; refrigerate.
Lower griddle to medium and oil the surface. Scoop ¼-cup portions, flatten to ½-inch thick, and cook 3–4 minutes per side until golden and set.
Garnish with extra cotija, cilantro, lime, and chili powder. Serve warm with the elote dipping sauce.