They might call it something else now. When I booked one in Aug for
MNSSHP, this was the wording they used:
Disney's Not-So-SpookySpectacular Dessert Party at Tomorrowland Terrace
On a further look, the “garden party” reservations have two different names, and events are only 2 nights apart, month of August. For HEA it’s called:
Magic Kingdom Fireworks Dessert Parties: Pre-Party
And MNSSHP:
Disney's Not-So-Spooky Spectacular Dessert Party with Plaza Garden Viewing
If searching for Dessert Party doesn’t get you anywhere, they might be sold out, or not yet able reserve.