Preheat the oven to 350F and lightly spray a 9×9 inch baking pan (see instructions above for 9x13). I like to line mine with a two sheets of parchment paper criss-crossed, with long ends, so I can lift the cake out later for easy slicing.

Mix the half-and-half with lemon juice and set aside.

In your stand mixer, cream the softened butter and sugar together for about 2 to 3 minutes, until light and fluffy.  You'll need to scraping the sides and bottom of your bowl occasionally. This step helps lighten and aerate the cake.

Then beat in the egg and extracts along with a tablespoon of flour (to keep it from curdling), followed by the baking powder, salt, and cinnamon.  Keep scraping the bowl.

Lower your mixer speed and blend in half of the flour, just barely mixing it in, then add the half-and-half, and finally the rest of the flour. Blend until the flour is *just* incorporated, and then stop---don't overmix.

Gently fold in the cranberries, making sure to get them evenly distributed but not crushed.  Be especially careful if you're using fresh (not frozen) cranberries, because you want to keep them whole.  If frozen, you can briefly pulse the mixer, but if fresh I'd stir them in by hand.

Spread the batter (it will be quite thick) evenly into your prepared pan. Sprinkle the sparkling or demerara sugar over the surface of the cake

Bake for about 50-60 minutes, until risen, golden, and a toothpick comes out without wet batter on it.  Start checking at 40 minutes to be safe, but this always takes 50-55 for me.  

Let cool for 15-20 minutes in the pan, then, if you used parchment, you can remove the cake to cool completely, or slice while still slightly warm.  I like to pull it onto a cutting board, use a giant chef's knife to cut it, then just lift the parchment easily back into the pan until I'm ready to serve.

Store the leftover cake in the pan on the counter covered with foil.