Combine the yeast, buttermilk and 1 tablespoon sugar and let sit until foamy.
Add the butter, remaining sugar, lemon zest, salt and cardamom in a mixing bowl.
Mix in the eggs and buttermilk mixture.
Slowly add flour and mix until all flour is moistened.
Let the dough rise until doubled in size, about 1 hour.
Make the filling by combining sugar, lemon zest, cardamom, and salt.
Assemble the rolls by rolling out the dough, spreading butter and sugar mixture, and rolling into a log.
Cut the log into 12 even pieces and place in a baking pan to rise.
Bake the rolls at 350 degrees for 30 to 35 minutes.
Make the icing by whisking cream cheese, powdered sugar, and lemon juice until smooth.
Spread the icing over the warm rolls and enjoy.