Adapted from a traditional Hungarian recipe.
In a large bowl (my grandmother recommends glass, for some reason), mix together the dry ingredients. Cut in the butter, then add the remaining ingredients (through the vanilla extract). Mix well, using your hands if necessary.
Divide the dough into 2 portions, then refrigerate for 1 hour.
Flour a board and roll out each dough portion. Cut the dough into 3-inch squares, and spoon the filling onto the center of each square. Roll straight and put on a greased or parchment-lined cookie sheet.
Optional: After rolling kiflis, brush top with milk and dip into a mixture of ground nuts and sugar.
Bake at 350 degrees for 15 minutes or until light brown. Cool and sprinkle with confectioners' sugar. Serve with coffee or tea.
Substitute thick fruit jam for the lekvar if necessary.