Bring a large pot of salted water to boil and cook 2 cups pasta according to package directions. Drain and return to the saucepan, toss with 1 tablespoon olive oil, and cover to keep warm.
While pasta cooks, whisk together 1/2 cup Greek yogurt, 2 tablespoons avocado oil, 1 teaspoon mustard, 2 teaspoons maple syrup, 1 teaspoon apple cider vinegar, 1/2 teaspoon onion powder, 1/2 teaspoon paprika, 1/2 teaspoon garlic powder, and 1/4 teaspoon salt in a small bowl until smooth. Set aside.
Heat 2 tablespoons oil in a large skillet over medium heat. Add 1 pound ground beef and season with 1 teaspoon paprika, 1 teaspoon garlic powder, 1/2 teaspoon salt, and a dash of pepper. Break up with a spatula and cook for 1-2 minutes.
Add 1/2 diced onion and cook for 3-4 minutes until softened and meat is almost cooked through. During the last 2 minutes, stir in 1/2 cup diced pickles until heated through. Drain excess grease and cover to keep warm.
In a medium saucepan over medium heat, melt 2 tablespoons butter. Add 3 minced garlic cloves, 1/2 teaspoon paprika, and 1/4 teaspoon salt. Cook for 1-2 minutes until fragrant.
In a small bowl, whisk together 1-1/2 cups milk with 2 tablespoons cornstarch until smooth. Pour into the saucepan and stir constantly for 3-4 minutes until slightly thickened.
Remove from heat and stir in 2 cups shredded cheddar cheese until melted and smooth. Stir in 1/2 cup Greek yogurt and 1/3 cup of the prepared Big Mac sauce until completely combined.
Add the cheese sauce to the cooked pasta and stir until well coated. Add the pasta mixture to the skillet with the ground beef and gently combine.
Serve immediately with a side salad made from 4 cups lettuce, 1/2 cup diced tomatoes, 1 ounce shredded cheddar cheese, and the remaining Big Mac sauce as dressing. Sprinkle with sesame seeds if desired.