Preheat an oven to 375°F. In a bowl combine the flour, baking powder, salt, cardamom, sugar, and lemon zest.
Take a box grater and grate the frozen butter into the bowl. Combine the butter with the flour until it resembles coarse meal.
Add the vanilla extract, lemon extract, and heavy cream. Mix until just combined (do not overwork it).
Transfer the dough onto the countertop and form into am 8-inch wide disc. Cut into 8 portions. Prepare a baking sheet with parchment paper and non-stick spray. Place each of the scones on the baking sheet.
Bake for 25-30 minutes or until golden brown.