This is ostensibly the recipe for peppermint patties, but it seems quite similar to the top of a mint slice biscuit too.
This is a very strange recipe, I mean, it's mostly dry ingredients that miraculously (by way of chemical interaction of the ingredients?) turn into peppermint patties. But I love Sweetapolita, and the amazing website, so when I saw this recipe, I knew it was worth a try.
4 cups icing sugar
45 grams unsalted butter
1/4 teaspoon peppermint oil
3/4 tsp pure vanilla extract
4 tablespoons evaporated milk
Using your mixer, preferably with a paddle attachment*, combine the butter, icing sugar, peppermint oil, vanilla, and evaporated milk and mix on low speed until it starts to come together. Then turn your mixer up! Probably to about 6/10 and mix for 2 more minutes.
Cover and chill in the fridge for 30 minutes and then roll out the mixture into small balls and press flat, into a patty shape. Cover and chill again - for about an hour.
I just used melted dark chocolate, but Sweetapolita's pastel shades are just adorable! Your choice.
*I don't know how well the recipe would work using normal beaters (ie a whisk), if you try it let me know!