Step 1

Set oven to 350F Butter a 9 inch spring form pan

Step 2

Step one is the only time consuming part of this cake. Wash your tangerines and put them in a saucepan covered with cold water. (They'll float, but don't worry about that) Bring to a boil, and boil for a full 15 minutes. The boiling removes the bitterness in the citrus skin.

Step 3

Drain and let the tangerines cool for a bit. Slice them in half, and then in half again. Remove any seeds and discard, but do this on a plate so you don't lose any juice or pulp. Put it all in a food processor and process until completely smooth. You may have to stop and scrape down the sides a few times. My finished puree weighed 11 1/2 oz, (about a cup) and I highly recommend weighing the puree and only using the 11 1/2 ounces. Too much puree will throw off the balance of ingredients in this cake.

Step 4

Set aside, or refrigerate until the next day if you want to do this ahead.

Step 5

The rest is a one bowl deal: Beat the eggs and sugar until light and creamy. Fold in the almond meal, orange pulp, baking powder, and Amaretto, if using. Mix until well combined.

Step 6

Pour into your prepared tart pan and smooth out evenly.

Step 7

Bake for 50-60 minutes, until lightly golden and a toothpick inserted in the center comes out clean. If the cake is browning too fast, cover loosely with a sheet of foil.

Step 8

Cool on a rack for 10 minutes, then remove from the pan to finish cooling.

Step 9

Dust with confectioner's sugar. Decorate with some citrus zest if you like.