Take a medium mixing bowl and combine together the blackberries, granulated white sugar and half of the flour i.e. ⅛ cup.
Prepare the topping in a separate bowl by stirring together the remaining flour, chopped walnuts, oats, cinnamon and brown sugar.
Now cut in 2 tablespoons of butter into the topping mixture using your hands or a pastry cutter. Squeeze the chunks of butter into the toppings mixture until well-combined and topping resembles large chunks.
Place four medium sized ramekins on a baking sheet and brush some butter inside.
First spoon the blackberry mixture evenly into the four ramekins. Then top each ramekin with some of the oat-nut-butter topping.
Bake at 180 C/375 F for about 25 minutes. Let them cool down a bit and serve warm. Add a dollop of whipped cream for some extra richness.
Recipe by Flavor Quotient at https://www.flavorquotient.com/2015/07/nutty-blackberry-crisps-summer-dessert/