Pre heat your oven to 170c and line your baking sheets with baking paper. Cream butter with sugars until smooth and creamy. Add in eggs, vanilla and yogurt and mix again until combined. Mix together milk, vinegar and bicarb and add it to the mixture. Add in your flour, and baking powder and beat until mixed through. Using a table spoon or small ice cream scoop, spoon out your filling keeping 1-2 inches between each spoonful. Place in the oven for 8-10 minutes. The whoopie pie will be done when they’re lightly golden and firm to the touch. Let them cool completely on the baking sheet.
Glaze coating
Mix 1 cup sifted icing sugar with enough water to make a runny glaze, add in colouring and mix through.
Buttercream Filling
Beat together butter and icing sugar. Slowly add in the cream and continue to beat until light and fluffy.
To assemble
Spread buttercream onto one side and sandwich with another. Swirl each side in the glaze and then roll in desiccated coconut. Be prepared to get your hands messy for this one.
Notes
Adapted from https://justbakedbyme.wordpress.com/2012/01/30/vanilla-whoopie-pies/