Python 2, 246 bytes
I have taken a similar approach to my answer at Calculate π with quadratic convergenceCalculate π with quadratic convergence . The last line takes the Nth power of pi and sums the digits. The N=5000 test takes a minute or so.
from decimal import*
d=Decimal
N=input()
getcontext().prec=2*N
j=d(1)
h=d(2)
f=h*h
g=j/h
a=j
b=j/h.sqrt()
t=j/f
p=j
for i in bin(N)[2:]:e=a;a,b=(a+b)/h,(a*b).sqrt();c=e-a;t-=c*c*p;p+=p
k=a+b
l=k*k/f/t
print sum(map(int,`l**N`.split('.')[1][:N]))
Some tests:
$ echo 1 | python soln.py
1
$ echo 3 | python soln.py
6
$ echo 5 | python soln.py
24
$ echo 500 | python soln.py
2305
$ echo 5000 | python soln.py
22852
The ungolfed code:
from decimal import *
d = Decimal
N = input()
getcontext().prec = 2 * N
# constants:
one = d(1)
two = d(2)
four = two*two
half = one/two
# initialise:
a = one
b = one / two.sqrt()
t = one / four
p = one
for i in bin(N)[2:] :
temp = a;
a, b = (a+b)/two, (a*b).sqrt();
pterm = temp-a;
t -= pterm*pterm * p;
p += p
ab = a+b
pi = ab*ab / four / t
print sum(map(int, `pi ** N`.split('.')[1][:N]))