Step 1: Prepare the Brownie Batter

1. In a microwave-safe bowl, combine ½ cup + 2 tbsp salted sweet cream butter and 4 oz chopped semi-sweet chocolate baking bar. Heat in 30-second intervals, stirring well after each interval, until melted and smooth, about 1-1 ½ minutes total.

2. Stir in ½ cup granulated sugar and ½ cup tightly packed light brown sugar until well combined.

3. Add 2 large eggs, one at a time, stirring well after each addition until fully incorporated.

4. Stir in 2 tsp pure vanilla extract.

5. Add ½ cup + 2 tbsp all-purpose flour (spooned and leveled) and stir just until combined, avoiding overmixing to maintain a fudgy texture.

6. Fold in 1 ¼ cups milk chocolate chips until evenly distributed.

   • Tip: Chop the chocolate bar finely for even melting. Use room-temperature eggs for better emulsification. Fold chocolate chips gently to avoid deflating the batter.

Step 2: Prepare the Slow Cooker

1. Lightly grease a 4-6 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 brownie batter into the slow cooker, smoothing the top with a spatula for even cooking.

   • Tip: Use a slow cooker liner or parchment sling for easy cleanup and removal. Ensure the batter is spread evenly to avoid uneven cooking.

Step 3: Slow Cook

1. Cover and cook on low for 2-3 hours or high for 1.5-2 hours, until the edges are set and a toothpick inserted in the center comes out with moist crumbs (not wet batter).

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 the Cake

1. Turn off the slow cooker and let the brownie cake cool in the insert for 10-15 minutes to set slightly, making it easier to remove or scoop.

2. Use the parchment sling (if used) to lift the cake out, or scoop portions directly from the slow cooker. Transfer to a serving platter if slicing, or serve warm from the slow cooker for a rustic presentation.

   • Tip: Cool the cake slightly before frosting to prevent melting. If serving warm, scoop directly for a cozy, gooey experience.

Step 5: Prepare the Peanut Butter Frosting

1. In a medium mixing bowl, use a handheld mixer or stand mixer on medium-high speed to beat 1 cup creamy peanut butter, ⅔ cup softened salted sweet cream butter, and 1 tsp pure vanilla extract for 1-1 ½ minutes, until smooth and creamy.

2. Add 2 cups powdered sugar, ½ cup at a time, alternating with 3 tbsp heavy cream, beating until fully incorporated and the frosting is smooth and spreadable.

   • Tip: Soften butter at room temperature for easier beating. Add cream gradually to achieve a spreadable or pipeable consistency. Beat until fluffy for a professional finish.

Step 6: Assemble and Serve

1. Spread or pipe the peanut butter frosting over the cooled or slightly warm cake using a spatula or a piping bag fitted with an open star tip (e.g., Wilton 1M). For piping, hold the bag ½ inch above the surface and swirl in a C-shape to create a star swirl effect.

2. Sprinkle ½ cup crushed Butterfinger candy evenly over the frosted cake. Place 6 halved fun-size Butterfinger candies decoratively on top.

3. Slice the cooled cake into 8-10 squares or wedges, or scoop warm portions into bowls or dessert cups (about ½ cup per serving).

4. Serve warm for a gooey, indulgent experience or at room temperature for a firmer texture. Pair with coffee, milk, or a dessert liqueur (like Kahlúa) for a decadent vibe.

   • Tip: Pipe frosting for a decorative look or spread for simplicity. Sprinkle Butterfinger pieces evenly for crunch in every bite. Serve in colorful bowls or plates to enhance the chocolatey theme.