Pastry Cream Buttercream (Crème Mousseline)

Pastry cream buttercream, also known as crème mousseline, is a luscious and rich frosting that combines the smoothness of pastry cream with the lightness of buttercream. It is a delightful fusion of flavours and textures that adds a luxurious touch to cakes, cupcakes, pastries, and other desserts.

To make pastry cream buttercream, you start by making a classic pastry cream. Please read my previous post to learn how to make pastry cream. Then, the pastry cream is mixed with butter. The addition of butter not only enhances the flavour but also gives the buttercream a smooth and spreadable consistency.

The combination of the pastry cream’s custard-like texture and the butter’s richness results in a luxurious and delectable frosting that pairs perfectly with cakes, cupcakes, or filling for pastries.

Pastry cream buttercream can be flavoured with various extracts, such as vanilla, almond, or citrus, to complement the overall taste of your dessert. It can also be tinted with food colouring for a decorative touch. Whether you’re frosting a birthday cake, filling delicate macarons, or layering a decadent pastry, pastry cream buttercream brings a touch of elegance and sophistication to any sweet creation. Its velvety texture and creamy flavour make it a favourite among pastry chefs and dessert enthusiasts alike.

Ingredients

500 ml (2 cups) milk
6 egg yolks
200 grams (1 cup) granulated sugar
40 grams (1/3 cup) cornstarch
1 teaspoon vanilla extract or vanilla bean paste
pinch of salt
350 g (1 1/2 cups) unsalted butter, cut into cubes and softened

Directions

Begin by making the pastry cream following the instructions provided earlier.

Once the pastry cream is cooked, chilled, and set, move on to the next steps. Remove it from the fridge and mix it a bit so that it becomes creamy again.

In a mixing bowl, beat the softened butter using an electric mixer or stand mixer until creamy and smooth.

Gradually add the chilled pastry cream to the softened butter, about a tablespoon at a time, while continuing to beat on medium speed. Make sure each addition is well incorporated before adding more.

Once all the pastry cream has been added, continue beating the mixture on medium-high speed until the buttercream is smooth, fluffy, and light in texture. This usually takes a few minutes.

Taste the buttercream and adjust the sweetness or flavourings as desired. You can add more sugar or vanilla extract according to your preference.

Once the pastry cream buttercream is well blended and the desired consistency is reached, it is ready to be used as a frosting or filling for your favourite desserts. Try out my perfectly moist vanilla cupcakes with this frosting, they are simply amazing!