Pre-heat oven to slow-moderate (155 degrees celsius (fan-forced)).
Prepare two small round, square or heart tins. Grease and dust with flour or grease and line with baking paper.
Separate egg whites from yolks.
Whisk whites using an electric hand held beater on medium-high speed until stiff.
Add egg yolks and continue beating for another three minutes.
Add sugar gradually to egg mixture while continuing to beat on medium-high speed.
Sift flour, cream of tartar and cornflour.
Fold dry ingredients through egg and sugar mixture on mixer's lowest speed.
Combine melted butter, boiling water and bicarb soda. Once combined, add to mixture and mix on lowest speed until combined.
Pour equal parts of mixture into the tins and bake for 45 minutes.
Once cakes are cooked, allow to cool for five minutes before turning out onto a cooling tray.