In the bowl of a stand mixer fitted with the dough hook attachment, combine the flour, sugar, yeast, salt, and nutmeg; mix on low speed for 1-2 minutes, or until thoroughly combined. Keeping the mixer speed on low, add in the egg, milk, water, vanilla, and butter; beat for 3-4 minutes, or until the dough begins to form a ball around the hook. Increase the speed to medium and continue beating for 8 minutes, or until the dough is smooth and shiny. Transfer the dough into the prepared large bowl, turning it once to lightly coat it in oil. Cover the bowl with saran wrap and set aside in a warm place for 2 hours, or until it doubles in size.
For the salted caramel:
In a medium-sized saucepan combine the butter, sugar, honey, and cream; bring to a simmer over medium-heat, stirring almost constantly until the butter is completely melted and the sugar is dissolved. Increase the temperature to medium-high and boil, stirring occasionally, until the mixture reaches 230 degrees (F). Remove from heat and pour the caramel into the bottom of a 9x13 inch baking pan. Set aside.
For the filling and assembly:
In small bowl combine the granulated sugar, brown sugar, and cinnamon; mix well to combine and set aside.
Lightly punch down the risen dough and transfer it to a generously floured work surface. Lightly dust the top of the dough with a little flour, then, using a lightly floured rolling pin, roll the dough out into an 18x10 inch rectangle. Brush the melted butter evenly over the dough, then sprinkle cinnamon sugar mixture over the dough.
Starting with the long side closest to you, roll the dough up like a jelly roll, keeping it as tight as possible. Lightly pinch the seam to seal the dough and turn the dough so it's seam side down. Using a piece of plain dental floss or a sharp knife, cut the roll into 12 equal pieces. Arrange the buns in the salted caramel sauce coated baking pan, placing them in four rows of three.
Cover the baking dish with saran wrap and set aside in a warm area for 1 hour, or until the buns have doubled in size.
30 minutes before baking, preheat the oven to 375 degrees (F).
When ready to bake:
Remove saran wrap and place pan in the preheated oven. Bake for 25-30 minutes, or until the buns are golden brown and the caramel is bubbling, rotating the dish halfway through to ensure even baking.
Remove the pan from the oven and let the buns cool in the pan for 10 minutes. After 10 minutes invert the baking dish onto a large serving platter, unmolding the buns with the salted caramel side up. Cool for another 10 minutes.
For the cream cheese frosting:
In the bowl of a stand mixer fitted with the paddle attachment, beat the cream cheese on medium-speed until smooth. Add in the vanilla, cream, sugar, and salt; beat smooth until all of the ingredients are fully incorporated. Spread the icing on top of the warm buns, top with toasted pecans and extra caramel sauce, if using, and serve warm.