To prepare a classic strawberry crumble recipe, first you need to prepare the ingredients. First, you'll need the following ingredients: 1 cup sliced strawberries 2 tablespoons granulated sugar 1 tablespoon cinnamon 1 teaspoon vanilla 2 cups rolled oats 1 tbsp. caster sugar 1/2 cup butter (or margarine) 1 1/2 cups confectioners' sugar (optional) 1/2 c. buttermilk Instructions: Preheat the oven to 350 degrees F. Line an 8x8x2-inch baking pan with foil or parchment paper and set aside. Sift the flour, baking powder, sugar, and salt into the bowl of an electric mixer. Beat the mixture on medium speed until it's light and fluffy, about 2 minutes. Add the butter and mix until the sugar is incorporated and the batter is well-combined. In another bowl, whisk the egg whites until they're stiff peaks. Gradually add the milk, beating well after each addition. Scrape down the sides of the mixing bowl as you go, scraping down any clumps of flour that remain. Pour in the melted butter, vanilla and sugar mixture, mixing just until combined. Spoon the strawberry mixture evenly over the pie crust. Sprinkle the top with shredded coconut. Bake for 35 to 40 minutes, or until just set. Allow to cool before cutting into squares. Serve with vanilla ice cream or whipped cream.