Prepare a charcoal or gas grill for direct cooking over medium heat. Stir together mayonnaise, 2 tablespoons sour cream, lime juice, garlic, ¼ teaspoon smoked paprika, and ⅛ teaspoon chili powder; set aside.

Brush ears of corn with 2 tablespoons softened butter. Grill corn for 8 to 10 minutes or until tender and slightly charred, turning and brushing every 2 to 3 minutes with remaining 2 tablespoons butter. Remove corn from grill; cool. Grill bratwurst alongside corn for 12 to 14 minutes or until 160°, turning often. Cut each lengthwise, then slice and set aside.

Lightly spray tortilla bowls with nonstick spray. Grill for 2 to 4 minutes or just until toasted, turning occasionally.

Cut corn kernels from cobs; toss corn with remaining ¼ teaspoon smoked paprika, remaining ⅛ teaspoon chili powder, and salt. Add green onions and feta cheese; toss to combine.

To assemble, spread mayonnaise mixture inside tortilla bowls. Add bratwursts and corn mixture. Place remaining 1 cup sour cream into a squeeze bottle or piping bag fitted with a round tip; squeeze or pipe sour cream on top or each to resemble football laces. Garnish with additional chili powder, if desired.