Preheat the oven to 325 degrees Fahrenheit. A bundt pan should be greased and floured. Remove from the equation.
Combine flour, baking powder, and salt in a large mixing basin. Remove from the equation.

At low speed, cream together butter and shortening in a large mixing bowl.

Alternate adding the eggs and sugar, mixing just until mixed after each addition, until the batter is bubbly.
Combine the vanilla and rum extracts in a mixing bowl.

Alternate adding the dry ingredients and buttermilk to the wet ones until the batter is mixed and fluffy.
To expel any air bubbles and level the top, spoon batter into the prepared pan and shake the pan a few times.
Bake on the middle rack for 1 hour and 15-20 minutes, or until a cake tester inserted into the center comes out clean or with moist crumbs adhering to it.
Remove the cake from the oven and poke holes in it with a fork, taking care not to go all the way through. Set aside some time
Melt butter in a saucepan over medium low heat to produce the syrup. Stir in the sugar and water until the sugar is completely dissolved.
Continue to whisk until the butter mixture foams up and thickens to the consistency of a loose syrup (do not boil). Remove the pan from the heat. In a separate bowl, combine the vanilla and rum essence.
Spread the butter mixture over the cake, ensuring it gets into the holes. (Save approximately 1/4-1/2 cup of the mixture to brush around the edges of the cake.)
Allow for a 10-minute rest period or until the syrup is no longer sticky. (If you leave it sitting for too long, the cake will stick to the pan.)
Carefully remove the cake from the pan and set it aside for an hour to enable the cake to cool and absorb the syrup.
Reheat the remaining syrup and drizzle it over the cake.