Step 1: Prepare the Oreo-Chocolate Base

1. In a food processor or zip-top bag, crush 12 Oreo cookies (without filling) into fine crumbs (1 cup). Set aside.

2. In a large bowl, whisk together 1 ½ cups all-purpose flour, ¾ cup granulated sugar, ¼ cup unsweetened cocoa powder, 1 cup crushed Oreo crumbs, 1 tsp baking powder, and ¼ tsp salt until well combined.

3. In a separate bowl, mix ½ cup melted unsalted butter, ½ cup milk, and 1 tsp vanilla extract until smooth. Add to the dry ingredients and stir until a thick, cake-like batter forms.

   • Tip: Remove Oreo filling to avoid excess sweetness. Crush cookies finely for even flavor. Mix batter gently with a spatula to avoid overmixing, ensuring a tender texture.

Step 2: Prepare the Cheesecake Layer

1. In a large bowl, beat 16 oz softened cream cheese with an electric hand mixer on medium-high speed for 2-3 minutes until light and fluffy.

2. Add ½ cup powdered sugar and beat until no lumps remain, about 1 minute.

3. Beat in ½ cup sour cream and 1 tsp vanilla extract until smooth.

4. In a separate bowl, whip ½ cup heavy whipping cream until stiff peaks form, about 2-3 minutes. Gently fold the whipped cream and 1 cup mini chocolate chips into the cream cheese mixture until just combined.

   • Tip: Soften cream cheese at room temperature for easier beating. Fold whipped cream gently to maintain airiness. Ensure chocolate chips are evenly distributed without overmixing.

Step 3: Layer in 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. Spread the Oreo-chocolate base batter evenly across the bottom of the slow cooker with a spatula.

3. Spoon the cheesecake layer over the base, spreading gently to cover evenly. Do not stir; the layers will meld slightly during cooking.

   • Tip: Use a slow cooker liner for easy cleanup. Spread cheesecake layer carefully to maintain distinct layers. Smooth the top for even cooking.

Step 4: Slow Cook

1. Cover and cook on low for 3-4 hours, until the cheesecake layer is set but slightly jiggly in the center and the base is cooked through (a toothpick inserted in the base should come out with moist crumbs).

2. Check doneness at the 3-hour mark; if the top looks too wet, remove the lid for the last 30 minutes to evaporate excess moisture.

   • Tip: Place a paper 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 5: Prepare the Ganache Topping

1. Place ⅓ cup semi-sweet chocolate chips in a heatproof bowl.

2. Heat 2 tbsp heavy whipping cream in a microwave-safe container on high in 15-second increments until just beginning to simmer (about 30 seconds total).

3. Pour the hot cream over the chocolate chips, ensuring all chocolate is covered. Let sit for 2-3 minutes.

4. Gently whisk until the chocolate is fully melted and the ganache is smooth and glossy. Set aside to cool slightly.

   • Tip: Chop chocolate chips coarsely for faster melting. Stir gently to avoid seizing. Prepare ganache just before serving for a pourable texture.

Step 6: Assemble and Serve

1. Turn off the slow cooker and let the casserole cool for 10-15 minutes to set slightly, making it easier to scoop.

2. Scoop the warm chocolate chip cheesecake casserole into 8-10 bowls or dessert cups (about ½ cup per serving), ensuring each portion has a mix of Oreo-chocolate base, creamy cheesecake, and mini chocolate chips.

3. Drizzle each serving with 1-2 tsp warm ganache. Optionally, sprinkle with extra mini chocolate chips or crushed Oreo crumbs for added crunch.

4. Serve warm for a gooey, indulgent experience. Pair with coffee, hot chocolate, or a dessert liqueur (like Kahlúa) for a decadent vibe.

   • Tip: Drizzle ganache in a zigzag for a polished look. Serve in wide bowls to showcase the creamy layers and glossy topping. Offer extra ganache or whipped cream on the side for customization.