Add the rolled oats, almond flour, dates, and coconut oil to a food processor. Process for 15-30 seconds, or until it forms a dough. It should not be too sticky or too dry, you can test the dough by pressing it between your fingers, it should hold together well.
Line the bottom of a 8-muffin tin with parchment paper (you don't have to if using a silicone mold). Press about 1 and 1/2 tablespoon of the crust mixture into each slot. You can shape it into a crust pie (like a cup), or just a flat bottom. Repeat with the remaining crust mixture. Transfer to the refrigerator and let it firm up slightly for at least 1 hour.
Combine the full-fat coconut milk, lime juice, maple syrup, cornstarch, lime zest, and agar in a medium saucepan. Whisk to dissolve the cornstarch.
Heat over medium heat, whisking constantly until it starts to boil and thickens. As soon as it thickens, remove from heat and whisk in the matcha if using.
Divide the lime filling evenly among the muffin slots. Let it cool for about 20 minutes at room temperature before transferring to the refrigerator. Refrigerate for at least 3 hours, or until the filling has set.
Serve fresh, topped with a dollop of coconut cream, or aquafaba meringue (see notes).
Lime pies are best served the same day but will keep for up to 2 days in the refrigerator.
Notes
For a crunchy crust, you can bake it (before adding the filling) for about 10 minutes in a 350°F preheated oven.
For the meringue: combine the aquafaba and vanilla extract in a small mixing bowl. Using an electric beater, beat until it forms firm peaks. Continue beating and add the sugar one tablespoon at a time until the meringue is glossy, smooth, and thick. Pipe about one tablespoon of meringue on top of each pie and brown using a hand-held torch. I recommend adding the meringue just before serving.