Place a pecan half in each muffin cup, top side down. In a medium bowl, combine the flour, baking powder, and salt and mix together thoroughly with a whisk or fork.
Make a well in the center. Pour the cream into the well. Use a rubber spatula to fold and stir the flour mixture and cream together just until the dry ingredients are completely moistened and a soft dough is formed. The dough won't look perfectly smooth. Let the dough rest for 2 to 3 minutes to firm.
Meanwhile, in a small bowl, mix together the sugar and cinnamon.
On a lightly floured surface with a floured rolling pin, roll the dough to a rectangle about 12 by 7 inches and 1/4 inch thick.
Use a small offset spatula or your fingertips to spread the dough with the soft butter, then sprinkle with a pinch of salt and the brown sugar, leaving a 1/8 to 1/4 inch border.
Starting at one short end, roll the dough tightly. Gently stretch the dough to lengthen the roll slightly to about 12 inches in length. Refrigerate for at least 30 minutes.
Preheat the oven to 400°F (204°C). Position an oven rack in the lower third of the oven. Lightly butter the muffin cups.
Cut the dough roll crosswise into 24 equal pieces. (It's easiest to do this by cutting the dough in half, then cutting each half in half, then cutting each portion into 6 pieces. This math is easier than it sounds.) Place each piece of dough in a muffin cup, cut side up.
Bake the sticky buns for 12 to 15 minutes, until browned. Rotate the pan(s) from front to back halfway through the baking time to ensure even baking. (The longer you leave them in the oven, the crisper the edges but the drier the dough.)
Immediately turn the buns out onto a sheet of parchment on a heatproof surface. (And we do mean immediately, otherwise the buns may stick to the pan.) Serve warm.