So I tried steeping the butterfly pea flower in water to extract some of the colour before adding it to the buttercream... it worked, but I would've had much more success with Suncore's Blue Butterfly Pea Supercolor Powder.

Once the cakes are ready consider adding a final flourish of decoration using sweets or sprinkles. Mini Smarties or Jelly Tots work a treat for kids (though the latter worked even better before Rowntrees suddenly make this sweet larger – where was the logic?) Taste-wise the Blue Velvet cake is similar to the famous Red Velvet. Both contain vanilla and a bit of cocoa which contribute for their special "velvety taste". And both are covered by scrumptious cream cheese frosting. How to make a blue cake naturally

The cake batter is very easy to prepare: you just have to combine separately the wet and the dry ingredients and whisk them together. Even a newbie won't be challenged. About the frosting Place the softened butter in a large bowl then beat with an electric hand-whisk until pale and fluffy. Gradually add the sugar and continue to beat until fully combined. Tender, moist, white cake with a pleasing light blue whipped cream filling that's not too sweet -- it's an angelic cake fitting for a baptism, a baby shower, or for everyday. Other roll cake recipes you may enjoy

The size of the eggs doesn’t matter too much (I always use medium) but just be sure you’re using free-range eggs. Blue Spirulina is another possibility. The colour intensity of the spirulina powder is a bit stronger than the Butterfly Pea. Start with 1 teaspoon added to the flour. If the final colour of the batter does not look perfect, you might add also another ½ -1 tsp. As a big fan of David Lynch's movie Blue Velvet, I've always dreamed of making a blue layer cake. But I don't like using artificial food dyes. And turns out that a natural blue cake is possible with the right ingredients. In this case I used Butterfly Pea Powder but you will find other options below.And the two small pieces of the removed cake are placed onto the filling to resemble butterfly wings. Keep with tradition and fill your cakes with a swirl of vanilla buttercream. This is the obvious way to go if making vanilla cakes. If serving butterfly cakes for afternoon tea consider adding crystalised flowers for decoration with sophisticated style. Put the paper cases into the bun tins before baking begins. Once the batter has been mixed the raising agent (baking powder) is activated, so getting the cakes into the oven as soon as possible is the best course of action to ensure you get light and fluffy buns. To make the buttercream, put the butter into a large bowl and beat with electric hand beaters until smooth and creamy. Sift in the icing sugar, then work it into the butter, starting slowly at first, then beating more vigorously once all the sugar is combined. Add the milk and the vanilla, then beat until creamy and smooth. If the mixture is too stiff, add a little more milk. You can colour the buttercream at this stage.