Brownie sundae.
That's about what makes this place the best place on Earth for me. The decadent chocolate brownie covered with vanilla ice cream and caramel sauce. It's the perfect treat for two (or three). It's such a large dessert, but I've always managed to finish because its just that good.
The atmosphere is also incredible. It's like a 50s ice cream shoppe even with the soda fountain. I tried a raspberry phosphate and it tasted just like a fizzy raspberry.
Also would definitely recommend their chocolates. They're a bit pricey, but I think well worth the money. They're quite large (unlike Godiva chocolates) and are perfect for a small treat.
Sweet moses is right across the way from Happy Dog (see other review), and is the perfect cap to a date night.