Preheat oven to 350 and line a baking sheet with parchment paper. Set aside.
Place cake mix, eggs and oil in a mixing bowl and beat. The batter will be stiff. Spoon batter into a pastry bag or gallon resealable freezer bag (make sure it's a freezer bag). Twist the open end and snip so you have ½" tip.
Pipe a heart shape onto the prepared parchment paper and bake for 8 minutes. Remove from oven, let cool on a baking sheet for 2 minutes before removing to a cooling rack to cool completely.
Once cookies are baked, match them up in pairs. Frost the bottom of one cookie and place another on top. Cookies are soft so it's easiest to frost them on a flat surface. Sprinkle valentine sprinkles around the edges and set aside.