PREP PAN: Take a 9" square baking pan and encase it entirely with heavy duty or quick-release aluminum foil (to make cleanup easy). Grease only the sides of the inside of the pan with non-stick cooking spray or use butter. Line a baking sheet with aluminum foil (to catch overflow).
Stir the yeast, water, and sugar, in a small bowl. Allow it to stand for about 5-8 minutes to dissolve the yeast.
Mix flour and salt together in a large bowl or stand mixer. Add the yeast mixture and stir to moisten the flour, scraping the sides of the bowl and folding the dough over itself until it gathers into a shaggy mass.
Move the dough to a lightly floured surface and knead it by hand for 5 minutes. Gently shape the dough into a loose ball, cover it with plastic, and let it rest on the table for 20 minutes. NOTE: This is a soft, moist dough. If the dough seems too stiff and hard to knead, add extra warm water 1 tablespoon at a time until you get a nice malleable dough.
Gently knead the dough on the lightly floured surface for 1-2 more minutes, or until it becomes smooth, supple, and elastic but not too firm (The texture of the dough should be soft but springy). Shape the dough into a loose ball, place it in a lightly oiled bowl, and turn to coat the top with oil. Cover it tightly with plastic wrap and let it rise at room temperature about 1 1/2 to 2 hours (until doubled).
Meanwhile make the caramel: in a small saucepan, melt the butter and then add the dark brown sugar over low heat, stirring occasionally, until the butter has melted and the sugar is completely moistened (it won't be dissolved). Whisk until the mixture looks silky and a little lighter in color.
Pour the caramel into the square pan, tilting the pan slightly so the mixture spreads evenly over the bottom of the pan. Set aside.
When the dough has doubled, gently pour it onto the floured work surface. Roll dough out to form a 9x9" square.
Spray dough evenly with non-stick cooking spray, leaving a 1/2-inch strip unsprayed along the top edge. Sprinkle the cinnamon sugar generously and evenly, then sprinkle with chopped pecans, again leaving the top 1/2-inch of the rectangle bare.
Starting with the bottom edge, roll up the dough jelly-roll fashion into log. (If the dough sticks to the table as you're rolling, use a dough scraper to loosen it gently). Pinch gently but firmly along the seam to seal.
Cut the log of dough into 4 equal pieces. Lay the pieces cut side down on top of the caramel. Don't worry if it's a tight fit. Let rise, uncovered, at room temperature for 1 hour or until the dough has almost doubled, (The rolls should fill the pan and extend 1/2 to 3/4-inch above it).
Meanwhile, position a rack in the center of the oven and preheat the oven to 350°F Bake for 30-35 minutes, until the tops of the buns are golden brown and crusty (It's important to bake the buns long enough so the dough is cooked all the way through and the caramel topping develops properly).
Set the pan of buns on a rack to cool for 5 minutes. Then quickly but carefully transfer the buns onto a heatproof plate. Immediately drizzle any remaining caramel from the bottom of the pan and spread it on the tops of the buns, filling in any bare spots (or drizzle with honey). Let the buns cool until just warm before serving.