Chocolate alfajores with Thermomix

Preparation

1. When you have gathered all those ingredients, follow the steps that we indicate:
2. Pour the sugar, cornstarch, flour and cocoa into the glass of the robot. Program a
3. speed 3/20 seconds.
4. Then add the butter in pieces and program at
5. speed 5/15 seconds.
6. Then add the rum and the egg. Put the robot to work
7. speed 6/15 seconds.
8. The resulting dough spread it well with a rolling pin and then cut the cookies with a round mold. Go putting them on a baking sheet, with the corresponding baking paper. And then put them in the oven at 170º for about 10 minutes.
9. After that time, take them out of the oven and let them cool. When they are done, go putting a little dulce de leche in half of them and then on those you place the other half of cookies or alfajores.