1-First Step: Crush 3 cups Corn Chex cereal lightly in a zip-top bag using a rolling pin. Aim for bite-sized pieces to retain crunch. Measure out 1 cup semi-sweet chocolate chips, 1/2 cup creamy peanut butter, 1/4 cup unsalted butter, 1 cup powdered sugar, and 7 oz marshmallow fluff. Having everything ready avoids scrambling mid-melt. Pro tip: Room-temperature peanut butter blends better.

2-Second Step: In a large microwave-safe bowl, combine chocolate chips, peanut butter, and butter. Microwave on high in 30-second bursts, stirring after each until fully melted and smooth, about 1-2 minutes total. Stir vigorously to prevent seizing. If no microwave, use a double boiler on stovetop over low heat. This creates the glossy chocolate peanut butter fudge core. Watch closely to avoid scorching, which ruins texture. Common mistake: Overheating leads to grainy fudge. Stir in vanilla extract if desired for extra aroma.

3-Third Step: Sift 1 cup powdered sugar into the warm mixture gradually, stirring until glossy and thick. Add marshmallow fluff next, mixing until no lumps remain. The fluff lightens the density, mimicking the airy puppy chow coating. For a simpler version, use 2 cups powdered sugar alone as in beginner recipes. Taste and adjust sweetness here, but sparingly since sugar intensifies as it sets. This step thickens fast, so work quickly. If too stiff, warm gently with 1 tsp milk.

4-Fourth Step: Gently fold in crushed Chex cereal with a spatula. Use broad strokes to coat evenly without crushing further. Pour into prepared pan, spreading flat with greased hands or offset spatula. Dust top with extra powdered sugar or sprinkles for looks and non-stick surface.

5-Final Step: Refrigerate for 2 hours until firm. Lift out using parchment, cut into 2×2-inch squares. Serve at room temp for best chew. Pairs with milk or coffee. Store as detailed later. Troubleshooting: Soft fudge? Chill longer or add more sugar next time. Soggy cereal? Fold gently and chill promptly.