WAFFLES: Combine the chocolate cake mix, eggs, water, and vegetable oil in a large bowl. Beat to combine, following package instructions. Preheat a waffle maker according to the manufacturer's instructions. I preheated mine to medium high.
COOK WAFFLES: Pour a heaping 1/2 cup of the cake mix into the waffle maker--or the correct amount to fill the baking area of the waffle iron correctly. Close and allow cake mix to cook. When it's finished cooking, remove and allow to completely cool on wire racks. Repeat this step until all waffles are made. I typically get eight large waffles from a prepared cake mix.
CREAM: In a large bowl, mix together the sweetened condensed milk and regular milk. With a hand mixer, blend in the pudding mix and then chill for 5 minutes. While it's chilling, make the whipped cream: add the heavy cream, powdered sugar, and vanilla paste (or extract) to a stand mixer bowl fitted with the whisk attachment. Whisk on low speed to combine. Gradually increase to high speed until medium to stiff peaks form, about 1-3 minutes. Watch carefully to avoid over-beating. With a spatula, fold this cream into the condensed milk and pudding mixture. Fold until smooth and combined. Place mixture in the refrigerator and keep chilled until the waffles are fully cool.
ASSEMBLE: Place one waffle on a cake stand or plate. Spread the pudding mixture on top (using about 1/5 of the mixture for each layer). Place another waffle gently on the pudding mixture. Add more pudding mixture. Continue this pattern with another waffle and more pudding mixture. Add the final waffle and the remaining pudding mixture on top.
GARNISH: If desired, garnish with fresh berries and chocolate shavings.
CHOCOLATE SHAVINGS: Make chocolate shavings by scraping a chocolate bar with a vegetable peeler. You can also break up some of the candy bar and place the chocolate chunks on top. Cut the cake into slices and enjoy immediately.