Step 1: Prepare the Cake Batter

1. In a large mixing bowl, prepare 1 box yellow cake mix according to package instructions (typically combining 1 cup water, ½ cup vegetable oil, and 3 large eggs with the mix). Whisk or beat with a handheld mixer on medium speed until smooth, about 2 minutes.

   • Tip: Use room-temperature eggs for better emulsification. Follow package instructions precisely for the best texture. Mix until just combined to avoid a tough cake.

Step 2: Prepare the Slow Cooker

1. Lightly grease a 6-quart slow cooker insert with cooking spray or a thin layer of butter to prevent sticking.

2. For easier removal, line the slow cooker with a parchment paper sling (two long strips crossed, overhanging the edges) and lightly spray the parchment.

3. Pour the cake batter into the slow cooker, spreading it evenly with a spatula.

   • Tip: Use a slow cooker liner or parchment sling for easy cleanup and removal. Ensure the batter is level to promote even cooking. A 6-quart slow cooker is ideal for this volume.

Step 3: Slow Cook

1. Cover and cook on high for 2.5-3.5 hours or low for 4-5 hours, until a toothpick inserted in the center comes out clean or with a few moist crumbs.

2. Check doneness at the minimum time; if the center is too wet, continue cooking in 15-minute increments. If the top looks too moist, remove the lid for the last 15-20 minutes to evaporate excess moisture.

   • Tip: Place a paper towel or clean dish towel under the lid to catch condensation and prevent a soggy surface. Avoid lifting the lid too often to maintain heat. Cooking times vary by slow cooker model.

Step 4: Cool and Poke the Cake

1. Turn off the slow cooker and let the cake cool in the insert for 15-20 minutes to set slightly, making it easier to poke and handle.

2. Use the parchment sling (if used) to lift the cake out onto a serving platter or leave it in the slow cooker for a rustic presentation.

3. Using a straw or the handle of a wooden spoon, poke holes evenly across the entire surface of the cake, about 1 inch apart, ensuring holes reach about ¾ of the way through the cake.

   • Tip: Cool slightly to prevent crumbling when poking. Space holes evenly to ensure pudding soaks uniformly. Use a straw for smaller holes or a spoon handle for larger ones, depending on desired pudding saturation.

Step 5: Prepare and Add the Pudding

1. In a medium mixing bowl, prepare 2 boxes (3.4 oz each) vanilla pudding mix according to package instructions (typically whisking with 4 cups whole milk for 2 minutes until thickened).

2. Spoon the pudding over the top of the poked cake, gently pressing with a spatula to encourage the pudding to fill the holes and cover the surface evenly.

   • Tip: Work quickly as pudding thickens fast. Spread pudding gently to avoid disturbing the cake. Ensure all holes are filled for maximum creaminess.

Step 6: Chill the Cake

1. Cover the cake (in the slow cooker insert or on a platter) with plastic wrap and refrigerate for 30 minutes, or up to overnight, to allow the pudding to soak into the holes and set.

   • Tip: Chilling helps the pudding firm up and enhances flavor melding. If using the slow cooker insert, ensure it fits in your fridge or transfer to a dish.

Step 7: Add the Chocolate Frosting

1. Microwave 1 tub (16 oz) chocolate frosting in a microwave-safe bowl for 30-60 seconds, stirring every 15 seconds, until smooth and pourable.

2. Pour the warmed frosting over the chilled cake, using a spatula or frosting knife to spread it evenly across the top.

3. Refrigerate the cake for an additional 30 minutes to set the frosting, or until ready to serve.

   • Tip: Warm frosting just until pourable to avoid melting the pudding layer. Spread quickly for a smooth finish. Chill to firm up the frosting for clean slices.

Step 8: Serve

1. Slice the chilled cake into 8-10 squares, ensuring each piece has a balance of cake, pudding, and frosting.

2. Serve cold for a refreshing, creamy texture. Pair with coffee, hot tea, or a dessert liqueur (like Kahlúa) for a decadent vibe.

   • Tip: Use a sharp knife dipped in hot water for clean slices. Serve on plates to showcase the layered effect. Garnish with whipped cream or chocolate shavings for extra flair.