Make the dough: Generously butter a large bowl and a 9x13 Baking Dish with 1 Tbsp. butter and set aside.

In a small Saucepan or Butter Warmer, heat buttermilk over medium heat until an instant-read thermometer reads 110F. Pour heated buttermilk into a medium bowl; the buttermilk will curdle a bit and separate—that’s expected. Whisk in 2 Tbsp. sugar and yeast and let sit for 10 minutes until foamy and puffed. Beat in the eggs.

Meanwhile, place the flour, remaining 4 Tbsp. sugar, and salt into a stand mixer  the dough hook attachment and mix medium-low. Pour in buttermilk mixture and mix on medium. Continue mixing until the dough just comes together. With the speed on medium, slowly add remaining 8 Tbsp. butter, 1 tablespoon at a time. Blend butter in well for a minute. Then mix on medium-high for 8 minutes; the dough will be quite sticky. Use a rubber dough scraper or spatula to scrape down the sides of the bowl and gather the dough.

Place the dough into the buttered bowl, cover with plastic wrap, and chill in the fridge for at least 4 hours and up to overnight.

Make the quick caramel: While the dough is rising, prepare the caramel. In the same Saucepan used to heat the buttermilk, heat butter over medium-low until melted. Remove from heat and whisk in light and dark brown sugars, maple syrup, bourbon (if using), and salt. Whisk until sugars are dissolved and mixture is cohesive. If sauce is not fully melted, return Saucepan to low, and continue whisking until dissolved. Pour sauce into the bottom of buttered Baking Dish, tilting to fully coat bottom. Sprinkle with chopped pecans. Set aside.

Make the spiced filling: Preheat oven to 250F. Remove dough from the fridge and let rest for 15 minutes. Roll out dough into a rectangular shape about ¼” thick on a well-floured surface with a floured rolling pin. Using an offset or rubber spatula, evenly spread butter all over rolled-out dough. Sprinkle brown sugars, cinnamon, and nutmeg over top. Starting at the long edge, roll dough toward you into a log, pinching gently to keep it rolled tightly. With seam side down, cut dough crosswise with unflavored floss or an oiled Chef Knife into 12 equally-thick rounds. Place rounds cut-side-up into the praline-lined pan, cover with plastic wrap, and place on top of oven. Let proof 1–1 ½ hours.

Increase oven temperature to 350F.

Beat egg in small bowl with bourbon or water to create an egg wash. Brush tops of buns with egg wash.

Bake until golden brown and cooked through, 40-45 minutes. If you have an instant-read thermometer, internal temperature from center of buns should reach at least 185F.

Remove from oven and allow to cool on a wire rack for 5 minutes and no longer (or they will be difficult to remove from the Baking Dish). Cover top of buns with parchment paper and a baking sheet and carefully flip over to remove buns. Serve warm or room temperature. Buns can be stored in an airtight container at room temperature up to 2 days.