For the filling, boil ¾ of the sour cherry juice with sugar.
Mix the rest of the juice with cornstarch and then blend in.
Add the sour cherries, stir briefly, then remove from heat.
Roll out the Danish pastry dough thin on a floured work surface and cut into 4x4in (11×11 cm) squares.
Brush the corners of the squares with egg and fold into the middle without closing them completely.
Spoon some of the cherry mixture with very little juice into the middle.
Beat the eggs with the granulated sugar until creamy and spoon a teaspoonful of the egg mixture over the cherries.
Sprinkle the grated almonds on top.
Place the kolaches on a slightly buttered baking sheet and bake at 400 °F (200 °C) at first and then lower to 340 °F (170 °C) and bake for about 15 minutes, depending on size.
