1. Place a rack in the center of the oven and preheat the oven to 350°F.
2. Lightly mist three 9-inch round cake pans with vegetable oil cooking spray, then dust them with flour. Shake out the excess flour. Set the pans aside.
3. Place the cake mix, orange gelatin, oil, eggs, and orange extract in a large mixing bowl. Add 1 1/4 cups of water, then beat with an electric mixer on low speed until the ingredients are moistened, 30 seconds. Stop the machine and scrape down the side of the bowl with a rubber spatula. Increase the mixer speed to medium and beat, scraping down the side again if necessary, until the batter is well blended and smooth, 2 minutes longer. Divide the batter evenly among the prepared pans, smoothing it out with a rubber spatula. Place the pans in the oven side by side or, if your oven is not large enough, place two on the center rack and the third pan in the center of the highest rack.
4. Bake the cakes until they spring back when lightly pressed with a finger, 18 to 22 minutes. Check the pan on the highest rack first; it will bake the quickest and may need to be rotated to a lower rack while it bakes. Remove the pans from the oven and place them on wire racks to cool for 10 minutes. Run a knife around the edge of each and invert them onto a rack, then again onto another rack so that they are right side up. Allow the cakes to cool completely, 15 to 20 minutes longer.
5. Meanwhile, start making the frosting: Place the sour cream and coconut in a large bowl, stir to combine, and place in the refrigerator, uncovered, for 1 hour.
6. Remove the bowl with the sour cream from the refrigerator, add the confectioners' sugar and orange juice, and beat with an electric mixer on medium speed until well combined, 30 seconds. Fold the whipped topping into the frosting until just combined.
7. To assemble the cake, place one cake layer, right side up, on a cake plate and spread some of the frosting over the top. Place a second layer, right side up, on top of the first. Spread some of the frosting over the top. Place the third layer, right side up, on top of the second layer, then frost the top and side of the cake smoothly and generously. Place the cake in a cake saver and refrigerate it until well chilled, 2 hours. Store this cake, in a cake saver or under a glass dome, in the refrigerator for up to 1 week.