Mix the sauce powder and 3 tablespoons of juice. Put the remaining juice and 2 tablespoons of sugar in a pot and bring to the boil. Remove the pot from the heat and add the sauce powder while stirring.
Bring to the boil. Add berries and fold in. Let the compote cool down. Meanwhile cook spaetzle in boiling water for about 15 minutes. Drain, rinse with cold water and let drain. Heat butter in a pan and fry the spaetzle in it until golden brown all around at medium heat.
Sprinkle with the remaining sugar. Arrange on plates together with the compote, dust with icing sugar and serve decorated with mint as desired.