Isaac's birthday fell on a Sunday this year, so we had a small celebration that evening. After all, he was still buzzing from the awesomeness of his Star Wars party from the day before. He had originally asked for a chocolate chocolate lemon cake (nope, not a typo). I managed to convince him to split up the flavors and have chocolate frosted cupcakes for his birthday party and a lemon cake for his birthday. As has been tradition since last year, I've frosted his cake simply and let him go nuts with the sprinkles.
1 cup sugar
1/4 pound unsalted butter, room temperature
4 extra-large eggs
1/2 cup lemon juice (3 to 4 lemons)
1/8 teaspoon kosher salt
Throw all the ingredients (yes, all!) into your blender. Cover and turn gradually from low to high speed like you're making a smoothie. Let it rip on high speed for about 6 minutes or until the mixture thickens and is hot. Keep an eye on it around the 5-minute mark and turn it off as soon as you see it thicken (blending too long will cook the eggs too much). You may have to turn the blender off for a moment to check it with your finger.
Adapted from The Barefoot Contessa Cookbook