Step 1 for the Caramel Sauce: Add the butter and brown sugar to a small saucepan and heat until butter is melted and sugar is dissolved.
Step 2 for the Caramel Sauce: Add buttermilk,, pecans and salt. Stir to combine.
Step 3 for the Caramel Sauce: Pour the pecan mixture into the bottom of a 9x13-inch pan coated with cooking spray. Set aside.
For the Filling: Combine the pecans, brown sugar, cinnamon and salt in a bowl and stir to combine. Set aside.
Step 1 for the Dough: In the bowl of your mixer, add the sour cream, buttermilk, sugar, egg yolk, vanilla, and orange zest.
Step 2 for the Dough: Beat on medium speed until smooth.
Step 3 for the Dough: Add the flour, baking powder, baking soda, and salt.
Step 4 for the Dough: Mix just until combined.
Step 5 for the Dough: Turn dough out onto well flour surface. Pat into a rectangle.
Step 6 for the Dough: Roll dough into 12x16-inch rectangle. Brush with remaining melted butter. Sprinkle with filling mixture. Using a pizza cutter, cut into 12 1-inch strips.
Step 7 for the Dough: Working with one strip at a time, tightly roll and place in prepared pan.
Step 8 for the Dough: Bake at 350° for 35-40 minutes.
Step 9 for the Dough: Remove from the oven and let sit for 5 minutes.
Step 10 for the Dough: Carefully invert sticky buns onto serving tray.