Buttery shortbread hearts are sandwiched with a sweet homemade raspberry jam filling. These classic Linzer cookies make a lovely holiday treat!
Place the frozen raspberries and sugar in a small pot and cook over medium-high heat, stirring, until the fruit has broken down and the mixture is syrupy.
Preheat the oven to 350 degrees F, and line a baking sheet with parchment paper.
Place the butter and sugar in a large mixing bowl, and cream together on medium-low speed until smooth.