Recipe video above. These special cookies are an Australian cafe favourite. Shortbread cookies joined with lemon buttercream frosting, they are beautifully buttery, lemony and true to their name, literally "melt in your mouth" unlike any other cookie I know!My cookies are generous sized because I like them big: 6cm / 2.4" diameter, 3.5-4cm / 1.5" thick. I wouldn't go any larger (too much cookie) but feel free to go smaller!
Preheat oven to 180°C / 350°F (160°C fan-forced). Line 2 trays with paper.
Cream butter - Place butter, vanilla and icing sugar in a bowl. Beat for 1 minute until smooth and fluffy (start on low to avoid an icing sugar cloud-storm).
Dry in 3 lots - Stir in cornflour and flour in 3 lots using a rubber spatula. (ie add 1/3 of flour + cornflour, stir in, repeat twice more).
Scoop 1 tablespoon of the mixture onto the trays (cookie scoop handy here), then roll into balls using lightly floured hands (to prevent it from sticking). You should have 24 - 28 balls.
Bake - Press down into 1 cm / 0.4" thickness using a fork. Bake for 15 minutes, switching the trays at the 10 minute mark. Fully cool on trays.
Sandwiching - Pipe frosting onto half the melting moments, then sandwich with remaining cookies.
Set - Refrigerate for 1 hour to set the frosting (else it's so soft, it squirts out!). Then remove from the fridge 30 minutes prior to serving.
Lemon icing:
Cream butter - Place butter in a bowl and beat with an electric mixer on medium high for 1 minute until smooth and fluffy. Add 1/3 of the icing sugar, then beat in starting on low and increasing to high (to avoid snow-storm!). Repeat another 2 times.
Beat 2 minutes - Add lemon zest and juice. Then beat on high for 2 minutes until fluffy. Transfer to piping bag, snip end off to make a 1cm / 1/2" hole. Use per recipe.
Passionfruit icing:
Same method as above for lemon icing.
Notes
1.Butter US measurement - You’ll need 17 tbsp of butter for this recipe which is 2 sticks + 1 tbsp.2. Icing sugar type - If you're in Australia, don't get pure icing sugar, sets hard like for royal icing. Get packet labelled SOFT icing sugar or "icing sugar mixture", or check the ingredients and ensure there's either cornflour/cornstarch, tapioca or similar as well as cane sugar/sugar.Storage - Keep in an airtight container for 4 to 5 days. It's best to store in the fridge but bring to room temperature before serving. Though if it's fairly cool weather, you can just keep in the pantry.Nutrition per Melting Moment. Remember, these are generously sized! :)