Beat eggs, condensed milk and brewed coffee with a mixer. Then add butter, salt and flour. Separately combine soda and lemon juice in a spoon and then add to the mixture. Mix well.
Spread the mixture evenly on parchment paper or a silicone mat, place in an oven preheated to 180 °C for 15 minutes. Roll the cake into a loose roll together with the paper and leave to cool.
Grind the yolks, flour, sugar and starch in a bowl. In a saucepan over low heat, mix the milk, coffee and starch mixture. Stir constantly until thickened.
Beat the butter with sugar and add to the mixture. Mix well and let cool.
Spread the cream on the cake, leaving some space around the edges, and roll into a tight roll. Decorate the top with the remaining cream.