Prepare the shortcrust pastry: combine all the ingredients except the cocoa in a bowl and work quickly, until you get a homogeneous dough.
Divide the dough in half and add the cocoa to one of the two parts.
Cover both loaves, separately, with cling film and leave to rest in the fridge for at least 30 minutes.
Take the loaves back, roll them out 1 at a time into a thin sheet and make your biscuits with a 4-5 cm round pastry cutter (work first on the light pastry, so that if the rolling pin and / or mold get dirty you will not stain the other pastry. ).
Try to make an equal number of black and white cookies, because they will be paired 2 to 2 after baking.
Arrange the biscuits on the baking sheet lined with parchment paper, slightly separated from each other, and engrave a small concentric circle in each biscuit, using a pastry cutter 1-2 cm smaller than the previous one, to remember the decoration of the real Ringos (if you want to overdo it, get the mold with the letter R and engrave that too, in the center of the second circle).
Bake for about 10 'minutes or until lightly browned in a preheated convection oven at 180 ° C.
Remove the cookies from the oven and let them cool completely (please, it's important, or the cream will melt).
Meanwhile, prepare the cream by simply whipping the butter with sugar and vanilla with a whisk.
Once completely cold, combine the biscuits 2 by 2 (1 white and one black) filling them with a layer of cream (press gently to make the biscuits adhere well to the cream).
The Ringo biscuits are ready, you just have to serve them.