1 (16.5-ounce) package white cake mix
3/4 cup water
1/2 cup vegetable oil
1/4 cup key lime juice
Zest of 1 key lime
1 (22-ounce) can key lime pie filling, divided
1 1/2 sticks butter, softened
1 teaspoon vanilla extract
4 1/2 cups confectioners' sugar
2 tablespoons graham cracker crumbs
Directions1.Preheat oven to 350 degrees F. Line 20 muffin cups with paper liners.
2.In a large bowl with an electric mixer, beat cake mix, eggs, water, oil, key lime juice, and lime zest until thoroughly combined. Spoon batter evenly into paper liners.
3.Bake 15 to 20 minutes, or until toothpick comes out clean. Let cool.
4.Using an apple corer or paring knife, cut a hole in center of cupcakes, being sure not to cut all the way through bottom; remove center. Reserve 1/2 cup of pie filling; fill holes evenly with remaining pie filling (see Note); set aside.
5.In a large bowl, beat butter, the reserved 1/2 cup pie filling, and vanilla until creamy. Gradually add confectioners' sugar and beat until smooth. Evenly frost cupcakes then sprinkle with graham cracker crumbs.