In a medium bowl, combine buttermilk, hot sauce and avocado slices. Soak for 30 minutes.
In a small bowl, combine the sour cream, lime juice, cilantro, red onion, Serrano pepper, and 1/2 teaspoon of salt. Stir to combine. Chill until ready to use.
In a medium Dutch oven or deep-fryer, fill oil to a depth of 3 to 4 inches (no more than halfway up the sides of the pan.) Heat oil to 375 degrees F over medium-high heat.
Combine cornmeal, flour, Essence, baking powder, and the remaining teaspoon of salt in a shallow dish. Dredge soaked avocado slices in the cornmeal mixture, shaking to remove excess cornmeal.
Place avocado slices in the hot oil and fry until golden, about 1 to 2 minutes each side. Using a slotted spoon, remove slices and drain on a paper towel-lined plate. Season with additional Essence. Serve immediately with spicy lime crema and garnish with lime wedges.