In a bowl add the heavy cream and vanilla. Beat with a hand whisk until slightly foamy, 1 to 2 minutes. Add the sugar or honey and beat until stiff peaks form--about 4 to 5 minutes.
Add 1/3 of the cream to the bottom of a 9x13 baking dish. Sprinkle over 1/3 of the berries.
Place a layer of graham crackers over the top of the berries.
Spread another 1/3 of the whipped cream over the crackers and sprinkle on another 1/3 of the berries.
Top with another layer of graham crackers.
Spread the last of the whipped cream and top with remaining berries. Cover and chill at least 4 hours but up to 24 to soften the graham crackers.
Notes
Note 1: For a refined sugar free option, use a light colored honey. Monkfruit could also be used in small amounts though I haven't tested it. Note 2: Choose a graham cracker free from high fructose corn syrup. I prefer Simple Mills Almond Flour Sweet Thins in Honey Cinnamon for a gluten free option or Annie's Brand Organic.