In a bowl, sift the all purpose flour, rice flour and corn flour. Whisk everything together and set aside.
In another bowl, add in butter and icing sugar. Mix just until well combined. Add in powdered milk and mix again just to combine. Add in egg yolk, vanilla extract and again mix just to combine.
Add in blended cornflakes and mix to combine. While still mixing, lower the speed of the mixer and add in flour mixture bit by bit, mixing just to combine as you go. Form the dough into a ball, cover with cling film when not using.
Take a pice of dough, flatten it a bit and place one almond in the center. Cover it with the dough and shape it into an oval log that is more or less thumb sized. Repeat for the rest of the dough. Place them on a baking tray with baking sheet.
Bake at 340ºF( 170ºC) preheated oven for 20-25 minutes or until the bottom edges are golden brown and they're fully cooked. Cool completely on a rack, around 40 minutes.