Preheat oven to 400 degrees Fahrenheit.
Chop the kumquats into very small pieces and set aside. Be sure to remove the seeds and the inner part that could be bitter (this batch of kumquats I found was super sweet!). Reserve a few slices to add on top of the scones before baking.
In a small bowl, whisk together the cream and the egg and then set aside. In a large bowl, whisk together the flour, baking powder, lemon zest, and salt. Stir in the kumquat pieces.
Rub the butter into the flour mixture, working until you have no lumps bigger than a pea.
Add the sugar and toss to mix.
Add the wet ingredients into the dry ingredients and stir to combine. Bring dough together gently with a wooden spoon.
Turn dough out onto a lightly floured counter and knead it no more than 12 times. [Apparently, twelve is the magic number here; surpass it at your own risk.]
Pat dough into a round approximately 1-inch thick, and cut into 8 wedges. (I used a round biscuit cutter this time). Add on the reserved kumquat slices. Place on an ungreased baking sheet or a Silpat.
Using a pastry brush, brush 1 tablespoon of the cream (or any sort of milk ) onto the wedges.
Bake for approximately 20-25 minutes, or until golden, or until a toothpick inserted in the middle comes out clean.