I know this is very late but we just went to a 4th of July BBQ this weekend.
I did a strawberry cheesecake - recipe from BBC Good Food. I put my strawberry puree in between the buttery biscuit base and the cheese layer so I could make the top look like the US flag. I was quite pleased with the result!
I also make cupcakes - colouring the batter and layering. I stole the idea for these cakes from here.
Lastly I tried to make red, white and blue striped strawberries but they didn't work out as well as I had hoped.
Carolyn from Cookin' For My Captain did a better job than me and gave me the idea.
And, no, I have no links to the great US of A other than having a Texan friend who has a BBQ every year but I am more than happy to join in the fun - any excuse for a BBQ with good friends and some frivolous dessert making!