- Preheat your oven to 350°F (175°C). Grease a 9x13-inch baking dish with cooking spray or butter. 
- In a large mixing bowl, combine the chocolate cake mix, chocolate pudding mix, water, vegetable oil, eggs, and vanilla extract. Mix until well combined and smooth, about 2-3 minutes. 
- Fold in the semi-sweet chocolate chips gently until evenly distributed. 
- Pour the batter into the prepared baking dish, spreading it evenly. 
- Bake in the preheated oven for 30-35 minutes, or until a toothpick inserted in the center comes out clean. 
- While the cake is baking, prepare the glaze by whisking together the powdered sugar and milk in a small bowl until smooth. 
- Once the cake is done, remove it from the oven and let it cool for about 10 minutes. Drizzle the glaze over the warm cake. 
- Serve warm or at room temperature, topped with whipped cream and chocolate shavings or sprinkles if desired.