Preheat oven to 300 F (150 C).

Mix sifted icing sugar and ground almonds into a bowl and set aside.

Beat egg white with mixer for 30 seconds until soft peaks form then add extra fine sugar (caster sugar) and keep mixing for another 4-5 minutes until very stiff peaks are formed and does not move even if you tip the bowl upside down.

Add vanilla extract and mix well.

Fold ½ the almond/icing mixture into the egg white and mix with spatula. Add other half and mix well with spatula making sure to scrape the edge of bowl. Gently bang the bowl on the bench top a few times to remove any air bubbles.

Spoon batter into piping bag, only half filling the bag, and pipe into wells of macaron baking mat.

Allow the macarons to sit for at least 15 minutes so they spread and dry out giving it a smooth surface when baked.

Bake for 15 minutes or until you can cleanly peel shells off the baking mat.

Remove from oven and cool.

Beat butter and pumpkin puree with mixer until smooth. Add vanilla extract, pumpkin spice and mix. Add powdered confectioners sugar (icing sugar) and mix well for 1 minute.

Scrape down the bowl, add cream and mix about 3 minutes until smooth and fluffy.

Match up macarons in pairs based on size. Fill a pastry bag with buttercream and pipe a quarter sized of buttercream into half of the shells, then sandwich them.