Preheat oven to 350 degrees. Butter a 12 cup bundt pan and cover sides and bottom with pecans. In a medium bowl stir together flour, pudding mix, baking powder, baking soda and salt. Set aside.
Using an electric mixer, cream butter and sugar. Stir in vegetable oil, eggs, vanilla extract, water and rum. Gradually add in flour mixture and blend until combined. Fold in chocolate chips and toffee bits. Pour batter into prepared bundt pan. Bake for 50 to 50 minutes, or until cake tester comes out clean. Cool slightly before adding 1/2 the glaze mixture, then cool completely before inverting.
For the Glaze:
Mix all ingredients together except the rum and cook on low heat until dissolved, stirring constantly. Remove from heat and add rum. Pour 1/2 of the mixture into slighly cooled cake before inverting. Remove cake from pan and pour remaining glaze slowly over turned out cake. Dust with powdered sugar.