Heat a grill pan over medium-high heat and spray with olive oil. Grill the corn, turning occasionally, until cooked and slightly charred in places, about 8-10 minutes. Remove from heat and let cool. Cut kernels from the cob, reserving about 2 ½ cups.
In a large bowl, whisk together the cornmeal, flour, baking powder, chili powder, garlic powder, and salt. In a separate small bowl, whisk the egg and milk together. Add the wet ingredients to the dry ingredients and stir to combine.
Stir in 2 cups of corn, chives, 2 tsp lime juice, and ¾ cup queso fresco into the batter.
In a small bowl, mix the remaining ½ cup corn, ¼ cup queso fresco, 1 tsp lime juice, and a pinch of salt to use as a topping.
Heat a cast iron or nonstick skillet over medium heat and brush with about 1 tsp olive oil. Spoon about 1 tablespoon of batter into the pan and flatten slightly. Cook for 3-4 minutes until golden brown, then flip and cook for another 2-3 minutes. Remove from the pan and repeat with the remaining batter. You should have about 32 fritters in total.
To make the cilantro lime yogurt, mix the yogurt, lime juice, and chopped cilantro in a small bowl.
Drizzle the cilantro lime yogurt over the fritters. Top each fritter with a spoonful of the corn and cheese topping, and garnish with extra chives and cilantro.