Preheat your oven to 325°F (163°C) and grease and flour a 10-inch Bundt pan.

In a large mixing bowl, combine unsalted butter, vegetable shortening, and granulated sugar. Beat together until light and fluffy, about 4-5 minutes.

Add the eggs one at a time, beating well after each addition.

In a separate bowl, whisk together flour, baking powder, baking soda, and salt.

Gradually add the dry mixture to the creamed mixture, alternating with buttermilk, starting and ending with the flour mixture.

Stir in the vanilla extract and fold in the toasted chopped pecans.

Pour the batter into the prepared Bundt pan and smooth the top.

Bake for 75-85 minutes or until a toothpick inserted into the center comes out clean.

Allow the cake to cool in the pan for 10-15 minutes before turning it out onto a wire rack to cool completely.

In a medium saucepan, melt the unsalted butter over medium heat. Stir in light brown sugar and heavy cream.

Bring to a boil, then reduce the heat and let it simmer for 1-2 minutes.

Remove from heat and mix in powdered sugar and vanilla extract until smooth, then let cool slightly.

Fold in chopped pecans before drizzling over the cooled pound cake.