Preheat oven to 325°F. Butter and flour a bundt pan to prevent the cake from sticking. Tap out any excess flour. In a large bowl of an electric mixer, beat the eggs, oil, water and rum just until mixed. Then add in the cake mix, instant pudding, flaxseed and cardamom and beat until you get a nice smooth mixture.
Pour the batter into your prepared bundt pan and bake for 55-60 minutes. Cake will have a light golden brown color. Once the cake has cooled for 5-10 minutes, make the glaze by melting butter in a medium sized saucepan. Then add the sugar and water and stir. Let this simmer for 2-3 minutes. Remove from heat and stir in the Bacardi rum. Pour into a 2 cup measuring cup and set aside for a moment. Using a fork, toothpick or skewer poke holes all around the bundt cake and slowly pour 1/2 cup of the glaze into the cake. (You will want something under the cake since the glaze might run down the sides).
The rum cake will start to absorb the glaze. MMMM. Add one more half cup of the glaze and wait a few more minutes to absorb it. Now, you can turn the cake over, remove the pan, poke more holes and repeat drizzling the glaze over slowly while you let it absorb. Sprinkle with powdered sugar or melted chocolate and enjoy. Cake is best left at room temperature.
Flaxseed & cardamom optional but add great flavor!