This Cosmic Chocolate Loaf Cake is a chocolate chip chocolate loaf drenched in chocolate glaze and fun rainbow chips.

This Cosmic Chocolate Loaf Cake is in honor of one my favorite store bought snacks.

The Internet is filled with tons of copycat recipes of the brownies.

So I knew that I wanted to do something different.

I know, shocking that I would want to do something different.

I already made a Cosmic Brownie Torte in my cookbook.

And I made it in fudge form here on the blog.

Since this is chocolate, chocolate, and more chocolate…you are so going to need a glass of milk to enjoy with the cake.

Serving with some ice cream is also a great idea.

Ingredient Highlights:

As always, the full recipe with measurements & directions can be found at the bottom of this post.

Sour Cream: Make sure to use full fat sour cream.
Pure Vanilla Extract: I always use Rodelle vanilla. They are by far my favorite vanilla.
Eggs and Egg Yolks: All recipes on the blog use large eggs unless indicated.
Vegetable Oil: I use vegetable oil in this to help make the cake moist. You can substitute melted butter but I do suggest you stick with using oil.
Heavy Cream: Heavy cream is to be use. No half and half. There is no substitute for this.
Unsweetened Dutch-processed Cocoa Powder: Again, I am a Rodelle baking cocoa girl through and through.
Semisweet Chocolate: I used semisweet chocolate in the loaf but you can use milk if you prefer.
Milk Chocolate Chips: I used a mixture of semisweet and milk chocolate chips for the glaze. You can use the mix or you can choose to go all semisweet or all milk chocolate.
Rainbow Chips: Rainbow chips are colorful candy coated chocolate pieces. They kind of taste like Sixlets if you have ever had those. You can use as many as you want.
Corn Syrup: Corn syrup in the glaze helps make it easier to cut.

Can you make this as mini loaves?
Yes, you can. You will need to adjust the baking time to about 30 minutes. I would start checking at that time and then just watch from there.
Can you make this in a different pan?
As long as it’s a loaf pan you can. I used a 12 inch loaf pan for a more dramatic effect for photo.
Do I have to use corn syrup?
You can skip it but it really does help the chocolate glaze cut better.
Can I just use semisweet chocolate?
I use a mix in the glaze but you can do either all semisweet or milk chocolate depending on your preference.
Can I freeze the loaf?
Yes, but not with the glaze on it. Save the glaze for the day you want to serve it.

Oven Thermometer – An oven thermometer will tell you if your oven is actually running at the temperature you set it to. Your oven may not be accurate. I have to calibrate my oven about 5 times a year. Now, granted, I use my oven more than most people but if you have not done it in awhile you should check it.
Room Temperature Ingredients – it’s always best when making a cake, and most baked goods, that the ingredients be at room temperature.
Don’t Over Bake – Make sure to keep checking with a wooden skewer or sharp knife. Chocolate cake in general runs a little drier, so you want to make sure you don’t overbake.
Line Your Loaf Pan With Parchment Paper: While baking spray is usually enough, I like the added security of the parchment paper to make sure the loaf is not sticking to the pan.

Last but not least…it’s a great time to buy my cookbook .

For the cake:
Preheat the oven to 350 degrees F.
Grease an 8 1/2 by 4 1/4 by 2 1/2-inch loaf pan with baking spray and use parchment paper with an overhang to make it easier to remove. I used a longer loaf pan (12 inch)https://amzn.to/496NxBr.
Sift together the flour, baking powder, unsweetened cocoa powder, and salt into 1 bowl.
Using a stand mixer with a paddle attachment beat the eggs, egg yolks, and sugar until the mixture becomes light in color and increases in volume, about three minutes.
Add the sour cream and vanilla extract and mix until incorporated.
With the mixer on slow add half of the flour mixture. Mix until combined.
Add the milk and vegetable oil and mix until combined.
Add the remaining flour mixture and mix until full combined.
Toss the chocolate chips in the 1 TBSP flour and mix to coat them (this will help with the chips not sinking).
Fold in the chocolate chips.
Pour the batter into the prepared pan and bake for about 50 minutes or until a cake tester placed in the center of the loaf comes out clean.
When the cake is done, allow it to cool in the pan for 10 minutes.
Carefully place on a baking rack over a sheet pan.
Let cake completely cool before adding glaze.
For the Glaze:
Place the cream and corn syrup in a small microwave-safe bowl and microwave on high for 1 minute.
Add in the chocolate chips.
Let stand for 3 minutes before stirring until smooth.
Pour over the cooled cake loaf.
Once glaze is on add as many rainbow chips as you want.