In a mixer, add the whipping cream, sugar, chocolate syrup, cocoa powder, and vanilla and whip until light and fluffy. Taste it to check for sweetness and chocolatiness; , if necessary, add a tiny bit more of each of the sugar or chocolate ingredients slowly.
On a dinner plate, spread 1/8 cup chocolate mixture on the bottom of the plate.
Lay 3 graham crackers on top.
Spread more frosting on top of the graham crackers to cover them.
Repeat until there is just enough frosting left to frost the top and sides of the stack of graham crackers;