Preheat oven to 325 degrees

Spray a large bundt pan (12 cup) with nonstick baking spray

In a large mixing bowl, combine flower, sugar, baking powder, salt and butter

On low speed combine ingredients until the mix is the consistency of fine gravel, and all particles are about the same size.

Add to the large bowl, the pudding mix, milk, eggs, ½ cup of rum, oil, and vanilla extract and combine on medium speed with electric mixer for 2 to 3 minutes, be sure scrape down the bowl halfway through.

At this point the batter should be really smooth, pour ½ the batter into your prepared bundt pan

Sprinkle in the chopped walnuts and then pour the rest of the batter into the bundt pan.

Bake for about 55 minutes- until fully golden and tooth pick comes out clean.

Remove from oven and place on a cooling rack while making the soaking glaze.

Combine butter, rum, water and sugar in a small saucepan over medium-high heat.

Bring to a boil carefully as mixture boils over very easily, whisking occasionally.

Reduce to a simmer and cook until sugar is dissolved and syrup is well combined and a little thicker.

While cake is still cooling, pour some of the hot syrup on top of the cake, allowing it time to soak in (this may take a while as there will be a lot of syrup) continue to add syrup until all of the syrup is added.

Allow cake to cool for about 10-15 minutes in pan before turning out onto serving platter. Be sure to use a large enough platter in case some rum glaze seeps out.