In a small mixing bowl, stir together cookie crumbs and 1 tbsp (15 mL) of melted butter. Divide cookie crumbs between four 4-oz (125 mL) mason jars. Use your thumb to gently pat down.
In a medium bowl, whisk together egg yolks, 1 cup (250 mL) of the sugar, lemon juice and zest. Transfer to medium saucepan. Over medium heat, gently whisk for 6 to 7 minutes, until curd begins to thicken. Whisk in remaining ½ cup (125 mL) of butter and continue to cook until curd is thick and coats back of spoon, about 2 minutes.
Remove from heat and spread lemon curd through a fine mesh sieve to remove zest. Spoon curd into each jar over ginger crumb base. Allow to cool. Place plastic wrap directly on surface and refrigerate until chilled and set, about 1 hour or until ready to serve.
Preheat oven to 350°F (175°C).
When ready to serve, in large bowl using a hand mixer, beat egg whites with cream of tartar until foamy. Slowly add in remaining ¼ cup (60 mL) of sugar a tablespoon (15 mL) at a time until egg whites become thick and glossy, about 5 minutes. Spoon over lemon curd. Place mason jars on a baking sheet. Bake for 10 to 15 minutes until meringue is golden brown. Let cool.
Made these and doubled the recipe; it made 4x 250 mL & 4x 125 mL mason jars, plus i had enough meringue left over to make a few meringue cookies. I used ground shortbread cookies for the base because I didn’t want the taste of gingersnaps competing with the lemon flavour. These were a big hit with our friends. I’ll definitely make this again!