1Preheat oven to 425°F (220°C). In a large bowl, whisk together the flour, polenta, salt, sugar, cayenne, and baking powder. Stir in 1 1/4 cups of the grated cheddar cheese and the diced jalapenos.
2Make a well in the center of the flour mixture. Pour the cream into the center of the well and your (clean) hands to gently bring together the ingredients. If you need to add a bit more cream then do so a tiny trickle at a time. You just want everything to get wet enough so that the dough will be sticky and clumpy.
3Turn the dough out onto a surface lightly dusted with flour. Knead the dough just a few times - maybe only three or four pushes. You just want it to come together. (Over-kneading will result in firmer, denser biscuits.)
4Form the dough into a disc about 3/4-inch to an inch thick. Use a biscuit cutter (or a small juice glass) to cut round biscuit shapes out of the disk. Combine the leftover dough and keep forming small round biscuit shapes until the dough is used up.
5Place on a Silpat-lined or parchment lined baking sheet, with at least an inch or two between the biscuits. Brush the tops of the biscuits with a little more cream. Top the biscuits with a sprinkle of the remaining cheese.
6Bake at 425°F (220°C) for 11-12 minutes or until golden and the cheese is nicely melted.