Ingredients

Chocolate Cake Base

  • 1 cup (125g) all-purpose flour
  • 1 cup (200g) granulated sugar
  • 1/3 cup (35g) unsweetened cocoa powder
  • 1 tsp baking powder
  • 1/2 tsp baking soda
  • 1/4 tsp salt
  • 1 large egg
  • 1/2 cup (120ml) whole milk
  • 1/4 cup (60ml) vegetable oil
  • 1 tsp vanilla extract
  • 1/2 cup (120ml) boiling water

Blue Vanilla Mousse

  • 2 cups (480ml) heavy whipping cream, cold
  • 1 cup (120g) powdered sugar
  • 8 oz (225g) cream cheese, softened
  • 1 tbsp vanilla extract
  • Blue food coloring (gel or liquid, adjust to desired shade)
  • 1 tbsp unflavored gelatin
  • 1/4 cup (60ml) cold water

Cookie Crumb Topping

  • 1 1/2 cups (150g) crushed chocolate chip cookies (store-bought or homemade)
  • 1/4 cup (60g) unsalted butter, melted
  • 1/2 cup (90g) mini chocolate chips (for garnish)

Decoration (Optional)

  • Candy googly eyes (or white chocolate with black icing for eyes)
  • Extra cookie crumbs for texture

Equipment

  • 8-inch (20cm) springform pan
  • Mixing bowls
  • Electric mixer or whisk
  • Spatula
  • Parchment paper
  • Small saucepan or microwave-safe bowl

Instructions

Step 1: Prepare the Chocolate Cake Base

  1. Preheat oven to 350°F (175°C). Grease an 8-inch springform pan and line the bottom with parchment paper.
  2. In a large bowl, whisk together flour, sugar, cocoa powder, baking powder, baking soda, and salt.
  3. Add egg, milk, vegetable oil, and vanilla extract. Mix until smooth.
  4. Carefully stir in boiling water (batter will be thin). Pour into the prepared pan.
  5. Bake for 25-30 minutes or until a toothpick inserted in the center comes out clean.
  6. Let the cake cool completely in the pan, then level the top with a knife if needed.

Step 2: Make the Blue Vanilla Mousse

  1. In a small bowl, sprinkle gelatin over cold water and let it sit for 5 minutes to bloom.
  2. Gently heat the gelatin mixture in a microwave (10-15 seconds) or small saucepan until dissolved. Set aside to cool slightly.
  3. In a large bowl, beat cream cheese and powdered sugar until smooth.
  4. Add vanilla extract and a few drops of blue food coloring, adjusting to achieve a vibrant Cookie Monster blue.
  5. Mix in the cooled gelatin until fully incorporated.
  6. In a separate bowl, whip the heavy cream to soft peaks.
  7. Gently fold the whipped cream into the cream cheese mixture until smooth and fluffy.

Step 3: Assemble the Cake

  1. Ensure the chocolate cake is cooled and still in the springform pan.
  2. Pour the blue mousse over the cake, spreading evenly with a spatula.
  3. Cover and refrigerate for at least 4 hours, or until the mousse is set.

Step 4: Prepare the Cookie Crumb Topping

  1. In a medium bowl, mix crushed chocolate chip cookies with melted butter until it resembles wet sand.
  2. Once the mousse is set, remove the cake from the refrigerator and carefully release it from the springform pan.
  3. Sprinkle the cookie crumb mixture generously over the top of the mousse.
  4. Scatter mini chocolate chips on top for extra texture.

Step 5: Decorate

  1. Place candy googly eyes or pipe white chocolate circles with black icing dots to create Cookie Monster’s signature eyes.
  2. Optionally, press extra cookie crumbs around the sides or on top for a messier, Cookie Monster-inspired look.

Step 6: Serve

  1. Slice the cake with a warm knife for clean cuts.
  2. Serve chilled, and store leftovers in an airtight container in the refrigerator for up to 3 days.

Tips

  • For a more intense blue color, use gel food coloring to avoid thinning the mousse.
  • Crush cookies to varying sizes for a textured, “munched” look.
  • If making homemade cookies for crumbs, bake them a day ahead to save time.

Serving Size