Warm the buttermilk in the microwave or on the stovetop, just until it is warm to the touch, about 105º to 115ºF. Place the buttermilk in a large bowl, or the bowl of a stand mixer. Add the yeast and lightly stir. Let it stand until the yeast is bubbling, about 10 minutes.
Add the eggs, 1 1/2 cups of the flour, softened butter, sugar and salt to the bowl with the yeast. Mix on low until combined. Continue adding flour, 1/4 cup at a time, until the dough comes together. It will still be slightly sticky. (You may not need to add all of the flour.) Change to the dough hook and knead for about 5 minutes, or turn onto a floured surface and knead by hand until soft and elastic, about 8 minutes.
Place the dough in an oiled bowl and cover. Let rise until doubled.
When the dough is almost doubled, make the caramel glaze.
In the bowl of a stand mixer, or with a hand mixer, combine the butter, both sugars, and the salt. Beat until light, about 2 minutes. Add the corn syrup and continue to beat until light and fluffy, about 5 minutes.
Spread the caramel mixture on the bottom of a 9x13-inch baking dish (preferably with tall sides). Sprinkle the pecans evenly over the caramel.
Once the dough has doubled, punch it down and pour out onto a clean counter that has been sprinkled with flour.
Roll the dough into a 18x12 inch rectangle. Spread the softened butter over the top, then sprinkle with the 1/2 cup of brown sugar and 1 teaspoon of cinnamon. Roll the dough, starting on the wide side. Cut the roll into 12 equal slices.
Place 12 slices of dough in the pan. Place the pan on a baking sheet to catch any caramel overflow. (Especially if your baking dish does not have high sides.) Cover the dish and let the rolls rise for 15-20 minutes.
Preheat the oven to 350ºF.
Bake the rolls for about 35-40 minutes, until golden brown and cooked through. I like to cover them about 20 minutes through so that they don’t get too dark. The caramel should turn a dark amber and be bubbling hot.
Remove from the oven and let them sit for 5 minutes, then turn out onto a platter to serve.
Notes
Nutrition information provided as an estimate only. Various brands and products can change the counts. Any nutritional information should be used as a general guide.