Preheat oven to 300 degrees.
If you don't have a food processor to crush up the graham crackers, you can put them into a large ziplock bag and use either a rolling pin or a meat crusher to break them up. Mix in the melted butter, brown sugar and nutmeg until well combined (Tip: use a rubber spatula).
Strain the egg yolks through a sieve (mesh strainer) if you have one into a medium pot. Add suagar and lemon juice, whisk to combine. Cook on low heat, stirring constantly with a wooden spoon, for 10-12 minutes or until it begins to thicken and coats the back of the spoon. Remove from the heat and stir for another minute. Add in butter one piece at a time, mixing until fully incorporated. Lastly, mix in the lemon zest and let the curd come to room temperature.
Pour the curd into the baked graham cracker crust, carefully wrap with aluminum foil (make sure not touch the top of the curd) and let cool in the fridge for about an hour.
Place blackberries in rows (or however you want to decorate it!) and grate fresh lime zest over top