Is it possible to combine magics in IPython / Jupyter?

Sometimes you want to use several magics at the same time. Now I know you can use

%%time
%%bash
ls 

But when I make my own commands this chaining doesn't work...

from IPython.core.magic import register_cell_magic

@register_cell_magic
def accio(line, cell):
    print('accio')
    exec(cell)

results in an error when using

%%accio
%%bash
ls

What should I use rather than exec?

from Is it possible to combine magics in IPython / Jupyter?