For the Brownies

1. Preheat your oven to 350 degrees Fahrenheit. Line a 9×13 pan with parchment paper and spray the paper and sides of the pan to ensure the brownies remove from the pan cleanly after cooling.
2. In a large bowl, whisk room temperature eggs, unsalted butter, vegetable oil, granulated sugar, light brown sugar, and vanilla extract together until smooth.
3. Carefully, use a whisk to mix all purpose flour, cocoa powder, and salt into the batter. Only mix until you see the chunks of the flour mixture disappear into the batter. Batter may appear lumpy and should look thick, but overmixing past when you see the dry ingredients incorporate into the batter will lead to drier brownies.
4. Pour batter into your prepared pan and use a spoon or knife to spread it across the pan evenly. Bake the brownies for 19-23 minutes or until a toothpick inserted into the center comes out with moist batter on it. The brownies will continue to bake and firm up as they cool.
5. Allow the brownies to cool fully before attempting to cut and frost. This could take a couple of hours.

For the Frosting

1. In a large bowl with a hand mixer or in the bowl of a stand mixer that is fitted with a paddle attachment, beat room temperature butter and powdered sugar together on low speed to avoid creating a mess. Beat until the mixture is smooth.
2. Add room temperature raspberry preserves to the frosting and mix on medium speed until incorporated. Use a rubber spatula to scrape down the sides and the bottom of the bowl before mixing again to ensure the jelly is spread evenly throughout the frosting.
3. If desired, transfer the frosting to a piping bag, zippable bag that you can snip the corner off of, or pastry bag for greater control when filling the sandwiches.

For Assembly 

1. After the brownies have fully cooled, use a knife or cookie cutter to cut the brownies into desired shapes. As long as all of the shapes are even, the shape does not matter. The smaller your shape, the more brownie sandwiches you will be able to create.
2. Use a sharp knife to cut each shape in half along the sides. For a heart, you would not cut down the center to create two “broken” halves of the heart, but you would cut it on its side to create two, full, thinner hearts. See the photos above for a photo representation.
3. Top the bottom halves of each of the shapes with raspberry filling using a knife, spoon, piping bag, or zippable bag with the corner cut off.
4. Place the top halves on top of each of the bottom halves to create brownie sandwiches with frosting stuffed in between.
5. Store brownie heart sandwiches at room temperature for up to 2 days tightly covered or in an airtight container or in the fridge for up to 5 days. Brownie hearts can be frozen in a freezer bag or container for up to 3 months.