Easy Raspberry Cake Filling

Ingredients

• 1.5 Tbsp (22mL) water

• 1.5 Tbsp (12 g) cornstarch

• 3 cups (12 ounces) fresh or frozen raspberries (DO NOT THAW)

• 1/3 cup (67 g) granulated sugar

• 1 tsp lemon juice

• 1/2 tsp pure vanilla extract

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Directions​

• Whisk the cornstarch and water together until all the cornstarch has dissolved. (I just use a fork to mix—very easy.) Combine cornstarch mixture, raspberries (no need to thaw if using frozen), granulated sugar, and lemon juice in a medium saucepan set over medium heat. Using a silicone spatula, stir the mixture, mashing the raspberries as they begin to thaw and soften.

• Bring to a boil and let it boil for 5 full minutes, stirring occasionally. Remove pan from heat and stir in vanilla extract.

• Allow the raspberry filling to cool at room temperature for 10–15 minutes, then transfer it to a bowl or container and place it in the refrigerator for at least 4 hours and up to 1 week (the longer, the better). 

• You can use the completely cooled and thickened raspberry filling to fill a 2-layer or 3-layer cake. You’ll have the most success with this raspberry filling if you partner it with some frosting filling; it really needs a buttercream base layer to keep the cake layers stable. Spread a thin layer of buttercream/frosting on your cake layers, to work as the sturdy base for your raspberry filling. Doesn’t need to be much; just a thin layer. You also need a buttercream “dam” around the cake layers to keep the jammy raspberry filling inside the cake layers. Spoon some buttercream into a piping bag fitted with a large round tip, such as Wilton 2A. Pipe a border around the cake. Then, spread the raspberry filling inside the buttercream border. An offset spatula is helpful for spreading. Assemble next cake layer on top, and repeat. For a 3-layer 8-inch or 9-inch cake, use a heaping 1/2 cup between each layer. For a 2-layer 8-inch or 9-inch cake, use about 3/4 cup filling; you’ll have some left over.