Answer
The molar mass of aspartame is equal to $294.3 \space g/mole$
Work Step by Step
Molar Mass ($C_{14}H_{18}N_2O_5$):
$C: 12.01g * 14= 168.1g $
$H: 1.008g * 18= 18.14g $
$N: 14.01g * 2= 28.02g $
$O: 16.00g * 5= 80.00g $
$ 168.1g + 18.14g + 28.02g + 80.00g = 294.3g$