Afterschool snacks can cater to more than just the kids. A few simple, sophisticated tweaks to classic treats — popcorn and peanut butter cookies — creates snacks everyone will enjoy. Spiced Butter Popcorn Start to finish: 10 minutes Makes 6 cups 6 to 7 cups popped popcorn 3 tablespoons salted butter 1½ teaspoons ground cumin 1 teaspoon curry powder 1 …