Preheat your oven to 350°F (175°C) and prepare two half-sheet pans with non-stick spray and parchment paper.

In a large mixing bowl, combine cake mix, sugar, water, eggs, vanilla, and oil. Beat until smooth, then add flour, salt, and sour cream until no lumps remain.

Divide batter evenly in pans and bake for 15-18 minutes until a toothpick comes out clean. Let cool for about 30 minutes, then refrigerate for 30-60 minutes.

Make filling by beating marshmallow creme and butter, then adding powdered sugar and cream until spreadable.

Cut cooled cakes into 32 heart shapes using a cookie cutter. Fill and stack hearts, then freeze for 1 hour.

Melt almond bark in a heatproof bowl over simmering water or in the microwave until smooth. Reserve some for drizzling.

Mix pink food dye into melted almond bark, then dip each frozen heart cake, allowing excess to drip. Place on rack to set.