Portillo's Chocolate Cake Milkshake is a decadent and beloved treat that combines their famous chocolate cake with creamy milkshake goodness. Here's a high-level summary of how you can recreate this indulgent shake at home:

### Ingredients:
- **Chocolate Cake:** A slice of rich, moist chocolate cake.
- **Vanilla Ice Cream:** About 2 cups, preferably a high-quality brand.
- **Milk:** About 1 cup, adjust for desired thickness.
- **Chocolate Syrup:** Optional, for extra chocolate flavor.
- **Whipped Cream:** For topping (optional).

### Directions:
1. **Prepare the Ingredients:**
- Ensure the chocolate cake is at room temperature. If it's not, you can warm it slightly in the microwave for easier blending.

2. **Blend the Milkshake:**
- In a blender, combine the slice of chocolate cake, vanilla ice cream, and milk.
- Blend until smooth and creamy. If the shake is too thick, add more milk a little at a time until you reach the desired consistency.
- For extra chocolatey flavor, you can add a squeeze of chocolate syrup before blending.

3. **Serve:**
- Pour the milkshake into a tall glass.
- Top with whipped cream if desired.
- Optionally, you can drizzle more chocolate syrup on top for presentation.

### Tips:
- **Cake Texture:** Blending the cake well ensures there are no large chunks, but some small bits of cake can add a nice texture.
- **Milk to Ice Cream Ratio:** Adjust the amount of milk to ice cream to achieve your preferred thickness.

### Recipe Sources:
- **[CopyKat Recipes](https://copykat.com/portillos-....chocolate-cake-shake Offers a detailed recipe with step-by-step instructions to recreate Portillo’s Chocolate Cake Milkshake.
- **[Insanely Good Recipes](https://insanelygoodrecipes.co....m/portillos-chocolat Provides a simple and straightforward recipe with tips for making the perfect shake.
- **[Chicago Tribune](https://www.chicagotribune.com..../dining/recipes/ct-p Features insights and a recipe inspired by Portillo's famous shake.

These sources will guide you in making a delicious Portillo’s Chocolate Cake Milkshake at home, ensuring you capture the rich, creamy, and indulgent flavor that has made it so popular. Enjoy your homemade treat!