Pour the cream into a saucepan and place on the fire.
Add cocoa and start mixing with a whisk until smooth.
Pour the condensed milk into the saucepan and start whisking for a few minutes. Remove from heat, stirring constantly. It is necessary to achieve a homogeneous cream. Add vanillin for flavor.
Pour the cream into a glass jar and store in the refrigerator. Serve with tea or spread it on biscuit layers.