• 1 tbsp. apple cider vinegar
To prepare steak: In a small bowl, combine 2 tablespoons chile powder, brown sugar, cumin, paprika, 1 tablespoon salt and 1 1/2 teaspoons black pepper. Pat steak dry, then massage it with olive oil and cover the entire surface with the spice rub. Transfer to a plate, cover with plastic wrap and refrigerate overnight. Let steak come to room temperature for at least 1 hour before cooking.
To prepare spiked sour cream: Combine sour cream, 1 tablespoon lime juice, 1 teaspoon chili powder and cayenne in a small dish and stir well. Season with small pinch of salt and pepper, and refrigerate.
To prepare salsa: In medium bowl, gently mix pineapple, avocado, onion, 1/4 cup cilantro, 2 tablespoons lime juice and vinegar. Season with 1/4 teaspoon salt, mix and cover with plastic wrap. Refrigerate.