Sprinkle the pecans in an even layer into the bottom of the pan
Whisk the butter, brown sugar, karo syrup and salt together in a sauce pan over medium heat until boiling. Continue whisking 15 seconds while it boils.
Add half the dry ingredients and mix on low speed until almost fully incorporated. Add the buttermilk and slowly mix to incorporate. Add the other half of the flour mixture then mix on low just until combined.