Step 1: Prepare the Whipped Cream

1. Chill a glass or metal mixing bowl in the fridge for 10 minutes.

2. Pour 1 ½ cups heavy whipping cream into the chilled bowl and beat with an electric mixer on medium-high speed.

3. Gradually add 2 tablespoons confectioners’ sugar and 2 teaspoons vanilla extract, continuing to beat until stiff peaks form, about 3–5 minutes.

4. Tip: Chill the beaters as well for faster whipping, and stop beating once stiff peaks form to avoid overwhipping into butter.

Step 2: Assemble the Cookie Stacks

1. Spread a generous teaspoon of whipped cream onto one side of each chocolate wafer cookie from the 9-ounce package.

2. Press cookies together to form stacks of about 3 inches tall (roughly 4–5 cookies per stack, depending on the package size).

3. Tip: Use an offset spatula or butter knife for even spreading, and work gently to avoid breaking the delicate wafers.

Step 3: Form the Cake Log

1. Spread a 1-inch-wide line of whipped cream down the center of a serving platter to act as a base.

2. Turn the cookie stacks sideways (so the layers are vertical) and join them end-to-end to form a log, placing them in the whipped cream line to secure.

3. Tip: Align the stacks carefully for a neat log shape, and press gently to ensure they stick together without collapsing.

Step 4: Frost and Decorate

1. Frost the entire cookie log with the remaining whipped cream, covering all sides evenly with a spatula for a smooth finish.

2. Sprinkle ¼ cup grated chocolate evenly over the frosted log for decoration.

3. Tip: Use a fine grater for delicate chocolate shavings, and chill the chocolate bar briefly for easier grating.

Step 5: Chill

1. Cover the cake tightly with plastic wrap or place in an airtight container.

2. Refrigerate for 8 hours to overnight, allowing the cookies to soften and the flavors to meld.

3. Tip: Ensure the cake is well-covered to prevent absorbing fridge odors, and chill for at least 8 hours for the best sliceable texture.

Step 6: Serve

1. Remove the cake from the fridge and slice diagonally into ½-inch thick pieces to reveal the zebra-like stripes.

2. Serve chilled on dessert plates.

3. Tip: Use a sharp knife dipped in hot water and wiped dry for clean slices, and serve immediately for the freshest texture.