PSpice cascode mosfet design not working properly
Sorry about the MOS symbol confusion... Here's a better answer:

I think there are three reasons why you get a very similar voltage gain. 

First off, your output resistance \$R_3\$ is quite low. The cascode transistor improves output impedance to allow a higher voltage gain, but there is no overall improvement since in the first circuit:

$$
r_{out} = R_3\parallel (r_{ds1}+10k) \approx R_3
$$

Adding a cascode transistor won't be able to improve this.

Secondly, the cascode bias voltage is probably too high. You want it to represent a large resistance. You can either alter the bias resistor network or use a diode coupled NMOS to ground (increasing it's length and adjust the current through it until you get a suitable setting).

Thirds, you should know you are limiting gain also with \$R_1\$. Effectively \$M_1\$ is acting like a source follower and the change in current through M1 is set by the voltage over \$R_1\$. Effectively you get the transconductance as \$g_m=1/R_1\$. 

Summing this up voltage gain in both circuits should be approximately 

$$
A_V=g_m r_{out} \approx R_3/R_1
$$