Happy New Year, everyone! Let’s jump right in with a super easy, very delicious and totally celebratory cake. (Are all cakes celebratory? Yes, yes they are.)

This ultra moist peanut butter cake is soft, springy, comes together quickly and tastes like a dream. It’s topped with a creamy, rich, silky frosting that’s basically whipped chocolate ganache and pushes all other frostings off the table. Just so good. Classic flavours in one very very addictive cake!

The recipe for the cake is adapted from the one in Weeknight Baking, a lovely cookbook by Michelle of Hummingbird High, one of my favourite food bloggers! The original recipe makes a larger cake than would fit in my cake pans and oven, so I cut it down to fit a standard 8″ square pan, tinkering with the ingredients a bit. I also turned it into a one-bowl recipe that doesn’t need a mixer (working with a smaller batter is one of the reasons this is possible) and the end result is just so unbelievably moist!

Michelle does say this cake doesn’t technically need a frosting and that’s very true, it’s so delicious on its own. But I couldn’t resist a chocolate frosting of some kind. Buttercream would have been the obvious choice but I wanted something quicker, that didn’t need room temperature butter or lots of powdered sugar. Enter, chocolate ganache! Whipping chilled ganache results in a thick, silky, fluffy frosting that’s actually a lot like buttercream but with an intense chocolate flavour.

Sprinkles are of course, optional, but also, not! No one ever said no to a fun pop of colour after all. Baked as a square cake, this still serves a group and makes 16 pieces. It stays moist even in the fridge since its an oil-based cake and just needs a few minutes for the ganache to soften a bit before you dig in.

The peanut butter flavour is perfect, the chocolate is perfect and overall, this might be my new favourite cake! (I say that each time, I know, but this is definitely up there!) I hope you’ll try this today 🙂

Please read the recipe notes before beginning.

Peanut Butter Cake with Whipped Ganache Frosting

Super moist and easy peanut butter cake frosted with creamy whipped chocolate ganache

Prep Time: 30

Cook Time: 25

Total Time: 55

Makes: 16 pieces

Print Recipe Pin Recipe

Ingredients

For the cake

1/2 cup milk (125 ml) + 1 tsp lemon juice
1/4 cup vegetable oil (60 ml)
1/2 cup peanut butter, at room temp (135 gms, see notes)
1 egg (I have not tried an eggless version)
1 tsp vanilla
1/3 cup water (80 ml)
1 cup brown sugar (200 gms)
1 cup plus 2 tbsps all-purpose flour (140 gms)
1/2 tsp baking soda
1/2 tsp baking powder
1/2 tsp salt

For the frosting

1/3 cup whipping cream (80 ml)
50 gms dark cooking chocolate, finely chopped

Instructions

First, combine the milk and lemon juice in a small bowl and set aside.
Preheat the oven to 175 C. Line an 8 inch square baking pan with non-stick baking paper, leaving a little overhang on two sides for easy removal.
Then in a mixing bowl, add the oil and peanut butter. Mix well with a silicone spatula or balloon whisk until combined.
Add the egg and vanilla, and mix till combined, followed by the water. Now pour in the soured milk, stir to combine and finally stir in the sugar until the mixture is fairly smooth.
Sift in the flour, baking soda, baking powder and salt. Fold to combine. The batter will look a little lumpy, but stir a little vigorously and it will become smooth. (If you're having trouble you can use a hand mixer here).
Pour the batter into the prepared pan. Bake for 25 to 30 minutes until the top is browned and a toothpick poked in the center comes out clean.
Let the cake cool in the pan for 15 minutes, then take out using the paper overhang and place on a wire rack to cool completely.
In the meantime, make the frosting. Heat the cream in a small saucepan until simmering, then pour over the chocolate (use a heatproof bowl). Let it stand for a couple of minutes, then stir until completely smooth. Allow to cool at room temperature for 10 mins, then transfer the bowl to the fridge, uncovered, for about 30 minutes until chilled through.
When ready to make the frosting, give the ganache a stir to loosen it up, then use a hand mixer to whip it for about 2 minutes, into a pale, creamy, fluffy frosting that forms soft rounded peaks when you lift the beaters (this is why whipping cream is recommended, regular cream won't produce the same peaks).
Spread immediately over the cooled cake and decorate with sprinkles if you like. Slice and serve! The cake, once frosted, should be stored in an airtight tin in the fridge and will last 4 to 5 days. Happy baking!

Notes

*Natural-style peanut butter is recommended here, the kind without any additives or preservatives. It's more liquidy and oily, keeping the cake moist. I like Butternut Co or Sundrop. However, if you only have the more processed variety at home, that's fine too, the results won't be dramatically different. Either way, the peanut butter should be at room temperature or just slightly melted so that it's easy to mix into the batter.

*Soft brown sugar works really well here because it produces a moister cake and dissolves better. I like Tate&Lyle brand. This cake is not overly sweet, so you can add 1/4 cup more sugar to the batter if you prefer.

*Whipping cream produces a fluffier frosting, but you can use regular cream if needed. If you choose to skip the frosting, stir some chocolate chips into the batter for extra flavour!

*Adapted from Weeknight Baking

Shop this recipe!

Check out a full list of my baking essentials here!

This post contains affiliate links.