Bring a large pot of salted water to a boil over high heat. You want it as salty as the ocean—don't skimp here because this seasons the shrimp from the inside out. Once it's rolling at a full boil, you're ready for the shrimp.

Add your 1 lb of large shrimp to the boiling water. Let them cook for exactly 3 to 4 minutes—they'll turn pink and start floating to the surface. Don't walk away at this point or you'll end up with rubbery shrimp (learned that the hard way).

Drain the shrimp in a colander and immediately transfer them to an ice bath—a bowl filled with ice water stops the cooking dead in its tracks. Let them sit in the ice for at least 2 minutes so they cool completely. This keeps them tender and juicy, not chewy.

While the shrimp cools, make your cocktail sauce. Pour the 2 cups of ketchup into a medium bowl and stir in 2 tablespoons fresh lemon juice, 1 tablespoon horseradish, and 1 teaspoon hot sauce. Mix it really well so everything combines smoothly.

Add 1 teaspoon sugar, 1/2 teaspoon smoked paprika, 1/4 teaspoon black pepper, 1/4 teaspoon salt, 1 teaspoon garlic powder, and 1/2 teaspoon onion powder to the ketchup mixture. Stir until you don't see any lumps and the sauce is totally smooth. Taste it and adjust seasonings if needed—this is your chance to make it perfect.

Fold the chopped parsley into the sauce gently so it stays pretty. I like to reserve a tiny bit of parsley to sprinkle on top when serving because it looks gorgeous. The sauce should taste bold and zesty, with that horseradish kick coming through.

Once the shrimp are completely cold and dry, arrange them around the rim of a serving bowl filled with ice, then place your cocktail sauce in the center. Guests can grab shrimp and dip them however they like. This classic shrimp cocktail is ready to impress immediately.