Submerge the cutlets in the pickle brine and refrigerate for 45 to 60 minutes, then drain and pat lightly dry.
Whisk the buttermilk and egg in one shallow bowl and combine the flour, cornstarch, garlic powder, pepper and salt in another.
Dip each cutlet in the buttermilk mixture, press it into the flour mixture and squeeze a few damp clumps of coating onto the surface.
Rest the breaded cutlets on a rack for 10 minutes while the oil heats.
Heat 1 inch oil in a wide Dutch oven to 350°F.
Fry two cutlets at a time for 3 to 4 minutes per side, keeping the oil near 340°F, until crisp and 165°F in the thickest spot.
Drain on a rack for 5 minutes rather than paper towels, which soften the bottom crust.