Ingredients
Scale
For the cake:
- 1 (15.25 oz) box yellow cake mix
- ½ cup (1 stick / 115g) unsalted butter, softened
- ½ cup creamy peanut butter (not natural/oily)
- 3 large eggs
- 1 cup water or milk
- 1 tsp vanilla extract
For the frosting:
- ½ cup (1 stick) unsalted butter, softened
- ½ cup creamy peanut butter
- 3 cups powdered sugar
- 2–3 tbsp milk or heavy cream
- 1 tsp vanilla extract
- Pinch of salt
For assembly & topping:
- 6–8 Butterfinger candy bars, crushed (about 2 cups)
- Optional: ½ cup semi-sweet chocolate chips + 1 tbsp coconut oil (for drizzle)
Instructions
- Make cake: Preheat oven to 350°F (175°C). Grease and flour two 9″ round pans or a 9×13″ pan.
- Beat cake mix, butter, peanut butter, eggs, water/milk, and vanilla until smooth (~3 min).
- Pour into pan(s). Bake:
- Layers: 25–30 min
- Sheet: 30–35 min
- Cool completely.
- Make frosting: Beat butter and peanut butter until creamy. Gradually add powdered sugar, then milk/cream, vanilla, and salt until fluffy.
- Assemble:
- Layer cake: Spread frosting between layers, then over top and sides.
- Sheet cake: Spread frosting evenly over cooled cake.
- Decorate: Press crushed Butterfingers onto sides and top.
- Optional drizzle: Melt chocolate chips + coconut oil; drizzle over cake.
- Chill 30 minutes to set (optional but helps slices hold).
💡 Pro Tips:
– Use regular peanut butter (like Jif)—natural PB can make frosting oily.
– Crush Butterfingers in a zip-top bag with a rolling pin for easy cleanup.
– Store covered at room temp up to 3 days or refrigerate for longer freshness.
Prep Time & Nutrition (per slice, serves 12):
Prep Time: 20 min | Cook Time: 30 min | Total Time: 50 min (+ cooling)
Servings: 12 | Calories: 380 | Net Carbs: 42g | Fats: 22g | Protein: 6g
Servings: 12 | Calories: 380 | Net Carbs: 42g | Fats: 22g | Protein: 6g