Bellagio (last visit: October 2012).
This was opened as part of Bellagio’s new Spa Tower expansion. Their pastries are wonderful – both beautiful and delicious. I can vouch for the cheesecake in white chocolate, Chocobana (chocolate mousse, caramelized bananas, dark chocolate cremeux, hazelnut dough), Opera (chocolate ganache, coffee butter cream, almond biscuit, espresso syrup), and the Pecan Tart (pecan caramel, espresso cream, pecan buttercream, hazelnut dough). The gelato is good, but not in the same league as the pastries. There are also crepes, breakfast pastries, and chocolate.
The only thing I haven't liked is a Nutella crepe (Nutella is a chocolate hazelnut spread). The crepe itself was fine, but it came slathered with much too much Nutella. It was sickly sweet and rich - and this coming from a guy that likes greasy food.
The famous chocolate fountain:
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