Step 1

Preheat oven to 375F. Generously grease a 8x4 inch loaf pan, and lightly dust with flour.

Step 2

Using a mixer on medium-high speed, cream the butter and sugar in a large bowl until very light and fluffy. Add the eggs, one at a time, beating well after each addition. Fold in the sour cream, vanilla, cardamom bitters and clementine zest.

Step 3

Fold in the flour, baking powder, salt and ground cardamom. Mix until just barely combined, making sure not to overmix - a few small floury streaks are okay. Pour the batter into the prepared loaf pan.

Step 4

Bake in preheated oven for 55-60 minutes, or until a toothpick inserted into the centre of the cake comes out clean. Let cool in the pan for 5 minutes, then carefully unmold and transfer to a wire rack to cool off completely.