It would be something different each time, depending on my time and tastes and the party. But the way I would find the recipe would be to go to my Facebook and search one of my friend's posts. She is ALWAYS posting pictures of recipes she has found or ones she has tried. She is from another country, so often the recipes she finds are in another language but the browser does a reasonable job of translating, especially with pictures to help. One of my friends loves looking through cookery books, so I might also ask her for a recipe.
Tip 1 - one word of warning - try it out FIRST, before taking to the party. I tried a new recipe one evening when I was hosting my friends. It was a fairly simple recipe of chocolate caramel squares (also called millionaire's biscuits). It needed condensed milk boiled in its tin for an hour (to caramelise it). Unfortunately, I used evaporated milk. I then watched the chocolate topping slowly slide sideways off the too soft caramel topping, to land in a gooey, sticky mess on the plate. needless to say, the chocolate caramel squares did not get eaten, however, the hungry gulls in the kitchen (otherwise known as my family) polished them off. Whenever my friends come round, the family gathers in the kitchen to wait for the leftovers! You'ld think they were never fed!
Tip 2 - make it SIMPLE and make it ahead of time. so it's just ready to serve. My favourite dessert (as opposed to desert, which is too sandy for my taste) is strawberries and cream. Nearly as welcome is strawberry cheesecake and cream.