Melt butter in a medium saucepan. Add pecans and cook, stirring frequently until pecans are fragrant.
Add brown sugar, whipping cream, and honey. Stir well and cook over medium heat until sugar is melted. Pour into a greased 9-inch square pan.
To make dough, dissolve yeast in warm water in a small bowl. Set aside.
In a large bowl, whisk together 2 1/4 cups flour, 1/4 cup light brown sugar, pumpkin pie spice, salt, baking powder, baking soda, and cinnamon.
Add butter cubes and cut in until the mixture is crumbly. Add pumpkin, buttermilk, vanilla extract and yeast mixture. Stir to mix.
Turn dough out onto a floured surface. Dough will be very sticky and you may need to work a little more flour into it, but try to use as little extra flour as possible.
Knead dough a few times and then pat or roll into a square that is approximately 9 inches.
Cut dough into 16 squares and arrange them over the pecan mixture.
Cover with plastic wrap and refrigerate overnight.
Set baking dish on the counter for 30 minutes.
Preheat oven to 400 degrees. Bake for 24 to 28 minutes. Immediately invert onto a serving platter.