Add the flour, one cup at a time, mixing on low until mostly incorporated before adding the next cup. Use a spatula to ensure all the flour is stirred in rather than over stirring the batter.
3 cups flour
Pour in your Sierra Mist while slowly mixing the batter until just incorporated.
2/3 cup Sierra Mist
Pour batter into prepared pan and bake in your 325 degree oven for an hour and five minutes to an hour and ten minutes, until your cake tester comes out with crumbs.
Let cool in the pan for 10 to 15 minutes. Turn pan sideways and tap to loosen, turning the pan to ensure you have the entire cake loose before turning out onto a plate to cool the rest of the way.
While the cake it cooling, mix together your glaze. Add the powdered sugar to a bowl, then add the lemon juice, lime juice, and Sierra Mist and stir with a fork until smooth. Pour carefully over the top of your cake, letting it drip down the sides.