Preheat the oven to 180°C / 350°F
Place peanuts and oats in a food processer and grind for about 30 seconds or until you get a crumbly peanut and oat mixture.
Add dates, salt and water and blend for another 30 seconds, or until the mixtures becomes sticky and clumps together.
Grease 6 tart shells with coconut oil or non-stick baking spray.
Divide the mixture evenly between the shells and use your fingers to flatten it against the bottom and sides.
Spoon one tablespoon of peanut butter into each tart shell and spread evenly on the bottom of crust.
Arrange the halved grapes, cut-side facing the peanut butter and skin side facing up, on top of the peanut butter. You can either arrange them in a single layer, or use more grapes and arrange them in a neat pile.
Place the tart shells in the oven and bake for 20-25 minutes, or until the crust is golden brown and the grapes have softened and are slightly wrinkled.
Remove the tarts from the oven and allow them to cool before removing from the shells and serving.
Best right after they’ve been made, you can store them in an airtight container, in the fridge for up to two days.