Preheat the oven to 350 degrees F and lightly grease 9-inch tart pan with removable bottom.

In large bowl, mix together oat flour, almond flour, coconut sugar and sea salt.

Add melted coconut oil and vanilla extract, mixing until a crumbly dough forms.

Press dough evenly into prepared tart pan, ensuring it covers the bottom and sides.

Bake 12-15 minutes until lightly golden. Let it cool while preparing the filling.

In medium saucepan, whisk together lemon juice, coconut sugar, corn starch and cold water until smooth.

Stir in coconut milk and lemon zest and cook over medium heat, whisking constantly until mixture thickens (about 5-7 minutes).

If using turmeric, whisk in now for a brighter yellow color. Remove from heat and let cool slightly.

Pour lemon filling into cooled tart crust, spreading evenly. Refrigerate at least 2 hours to set.

In clean mixing bowl, combine aquafaba and cream of tartar. Using an electric mixer, beat on high speed until soft peaks form (about 5 minutes).

Gradually add powdered sugar and vanilla extract, continuing to beat until stiff peaks form.

Once the lemon tart has set, spread or pipe aquafaba meringue on top of tart.

Optional: Use a kitchen torch to lightly toast meringue or place tart under a preheated broiler for 1-2 minutes, watching closely to prevent burning.

Serve immediately or refrigerate until ready to enjoy.