With the rack in the middle position, preheat the oven to 180 °C (350 °F).
In a bowl, combine the flour, baking powder and half the sugar.
In another bowl, beat the egg whites with an electric mixer until soft peaks form. Add the remaining sugar and beat until stiff peaks form. Set aside.
Make a well in the centre of the dry ingredients and add the egg yolks, oil, vanilla and milk. Blend well with the electric mixer.
With a spatula, fold in the egg whites until just incorporated.
Fill the cones up to the edge with batter. Place on a baking sheet.
Bake for about 20 minutes or until a toothpick inserted in the centre of the cake comes out clean.
Cool, then frost.
In a bowl, beat the butter, icing sugar, milk and vanilla until smooth. Divide the frosting into thirds. One part will be used as is, add cocoa powder in the second for a chocolate frosting and red food coloring in the third, to mimic strawberry ice cream. Frost the cakes.