Preheat your oven to 325°F (165°C). Grease and flour a Bundt pan.
In a large mixing bowl, cream the softened butter and granulated sugar together until light and fluffy.
Add the vegetable oil and mix until well combined.
Beat in the eggs, one at a time, ensuring each egg is fully incorporated before adding the next.
In a separate bowl, whisk together the flour, baking powder, baking soda, and salt.
Gradually add the flour mixture to the butter mixture, alternating with the milk and rum. Begin and end with the flour mixture.
Stir in the vanilla extract.
Pour the batter into the prepared Bundt pan and smooth the top.
Bake in the preheated oven for 55-60 minutes, or until a toothpick inserted into the center of the cake comes out clean.
Allow the cake to cool in the pan for about 10 minutes, then invert it onto a wire rack to cool completely.
In a medium saucepan, melt the butter over medium heat.
Stir in the granulated sugar and water. Bring to a boil, stirring constantly.
Reduce the heat and let the mixture simmer for about 5 minutes, stirring occasionally, until it thickens slightly.
Remove from heat and stir in the rum and vanilla extract.
Place the cooled cake on a serving plate.
Slowly pour the warm glaze over the cake, allowing it to soak in. You can use a skewer to poke small holes in the cake to help absorb the glaze.
Allow the glaze to set before serving.
Enjoy your meal!