Preheat the oven to 325°F. Generously grease and flour a 12 cup bundt pan. Place the butter and the sugars in a mixing bowl and beat with a mixer until fluffy. Add the vanilla and then the eggs, one at a time, beating well between each addition.
Stir together the flours, salt, and baking powder in a medium size bowl. Add half of the dry ingredients to the mixer and beat to combine. Add the milk slowly, while continuing to mix the batter. Add the remaining flour and beat just until combined. Stir in the toffee bits and pecans, if desired.
Spoon the batter into the prepared pan and bake for 65-70 minutes, until a toothpick comes out clean. Cool the cake in the pan for at least 30 minutes, before removing it from the pan. Let it finish cooling completely over a wire rack. Spoon warm Caramel Glaze over the cooled cake. Enjoy!
Notes
You will need one batch of this Caramel Glaze for the icing.