Step 1: Slice the yellow squash into 1/4-inch thick rounds. Arrange them in a single layer on a wire rack set over a baking sheet. Sprinkle both sides with 1 teaspoon of salt and let them sit for 15-30 minutes to draw out moisture. Pat thoroughly dry with paper towels.
Step 2: In a shallow bowl, whisk together the eggs and milk. In another shallow dish, combine the self-rising flour, cornmeal, 1/2 teaspoon black pepper, and garlic powder (if using). Mix well.
Step 3: Working in batches, dip each dried squash slice into the egg mixture, letting excess drip off. Then, transfer to the flour-cornmeal mixture, pressing gently to ensure a thorough and even coating. Place breaded slices on a clean plate or wire rack and let them sit for 5-10 minutes; this helps the coating adhere.
Step 4: Heat 3-4 cups of vegetable oil in a large, heavy-bottomed skillet (cast iron works best) over medium-high heat until it reaches 350°F (175°C). The oil should be about 1/2 inch deep.
Step 5: Carefully place the breaded squash slices into the hot oil in a single layer, making sure not to overcrowd the pan. Fry for 2-4 minutes per side, or until golden brown and crispy.
Step 6: Using tongs or a slotted spoon, remove the fried squash from the oil and place them on a clean wire rack lined with paper towels to drain excess oil. Immediately sprinkle with a little extra salt to taste. Repeat with the remaining squash, ensuring the oil returns to temperature between batches.
Step 7: Serve hot and enjoy your crispy fried squash!