Preheat your oven to 325°F (163°C). Grease a 9x5-inch loaf pan and lightly dust with flour. Toast the chopped pecans in a dry skillet over medium heat for about 5 minutes, stirring frequently until fragrant and lightly browned.
In a large bowl, cream together the softened butter and granulated sugar with an electric mixer until light and fluffy, about 3 to 5 minutes.
Add the eggs one at a time, beating well after each addition to incorporate fully.
In a separate bowl, whisk together the all-purpose flour, baking powder, and salt.
Alternately add the flour mixture and sour cream to the butter mixture, starting and ending with the flour. Mix on low speed just until combined after each addition. Avoid overmixing.
Stir in the vanilla extract evenly. Gently fold in the toasted pecans and toffee bits using a spatula.
Pour the batter into the prepared loaf pan and smooth the top. Bake for 70 to 80 minutes, or until a toothpick inserted in the center comes out clean or with a few moist crumbs.
Allow the cake to cool in the pan for about 15 minutes, then transfer to a cooling rack to cool completely before slicing and serving.