get phantom dessert pangs for their cupcakes. YUM.
Literally the best cupcake I've ever eaten. The actual cake is deliciously moist, dense, and super fresh. I hate airy cupcakes, as they tend to be more air than cake. It is the right amount of flavor without being overwhelming or tasting processed. It doesn't try to dominate the flavor of the frosting. They offer simple and basic cupcake flavors with a rotating list of frostings which are delicious. Expensive? Yes. But if you know anything about Park Slope, people are willing to pay for quality.
Other thoughts: This is not a bakery, so there is no variety of baked goods. The decor is nothing to write home about, but it's not a restaurant so who cares. Don't bother with the hot chocolate- I think it's just the hot chocolate mix they sell with hot milk. The girl behind the counter was super nice and friendly both times I went.
Walking down the street in Park slope, I sometimes get phantom dessert pangs for their cupcakes. YUM.