Preheat oven to 350F (175C). Set an oven rack to the center position.

Measure out 1 cup of nut flour and pour it into a large bowl. Set the bowl aside.

Place the graham crackers into a sealable sandwich bag. Using a rolling pin, crush the graham crackers into crumbs. Pour graham cracker crumbs into the bowl with the nut flour.

Add the cinnamon and salt to the bowl and stir until everything is incorporated. Add the melted butter and honey and stir until you get a mixture that looks like wet sand.

Divide the mixture into 4 mini tart pans. You'll need about 1/2 cup of the mixture for each pan. (My pans were 4.75 inches in diameter.)

Place tart pans onto a baking sheet and bake the crusts for 10 to 13 minutes, until the crusts start to turn golden brown.

Prepare the lemon curd while the crusts are baking. In a medium bowl, mix the egg yolks, sugar, lemon juice and lemon zest together. Set the bowl aside.

In a small saucepan, melt 4 tablespoons of butter over medium-low heat. Add the lemon and egg mixture and stir to combine the ingredients. Stir the lemon curd frequently to avoid overcooking the eggs. The lemon curd is ready when it coats the back of a spoon, about 10 to 15 minutes. Remove the lemon curd from heat.

Pour the lemon curd through a fine mesh strainer to strain out the lemon zest. Then, divide the lemon curd into the 4 tart pans.

Let the tarts cool at room temperature for 20 minutes before chilling them in the refrigerator for an hour. If you are in a hurry, just stick them into a refrigerator immediately.

Remove the tarts from the pan once they are chilled. Leftover tarts can keep in the refrigerator for 4 to 5 days.