Prep and Bake the Cake:
Preheat oven to 350°F. Line two 18×13-inch half sheet pans with parchment and spray lightly.
In a large bowl, mix the cake mix, cornstarch, sugar, water, eggs, vanilla, and oil for 1 minute. Add flour, sour cream, and salt. Mix on medium speed for 2–3 minutes until smooth.
Divide batter between the pans and smooth out evenly. Bake 15–18 minutes, until cooked through. Cool at room temp for 30 minutes, then refrigerate for 30–60 minutes.

Make the Filling:
Beat the marshmallow creme and butter until creamy. Add powdered sugar, vanilla, and salt. Mix until fluffy. Add cream, 1 tbsp at a time, until spreadable (not runny).

Assemble the Cakes:
Cut cooled cake into 2-inch hexagons (or circles) using a cookie cutter. Dust the cutter with flour to prevent sticking.
Spread filling onto half the pieces, then sandwich with the rest. Place assembled cakes on a parchment-lined tray and freeze for 1 hour (or up to 24 hours).

Coat the Cakes:
Melt almond bark in 30-second bursts in the microwave, stirring between each. Stir in Crisco until smooth.
Dip frozen cakes into coating and place on a rack lined with parchment.

Decorate:
Melt the chocolate wafers and drizzle over cakes using a piping bag fitted with a small round tip. Let set completely before serving.