Yo boy, must it sum

Brachylog, 7 bytes

~+ℕᵐ.↔ᵐ

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Surprisingly not that slow.

Explanation

(?)~+  .          Output is equal to the Input when summed
     ℕᵐ.          Each element of the Output is a positive integer
       .↔ᵐ(.)     When reversing each element of the Output, we get the Output

Python 2, 82 79 bytes

f=lambda n:min([f(n-k)+[k]for k in range(1,n+1)if`k`==`k`[::-1]]or[[]],key=len)

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Jelly, 12 10 9 8 bytes

ŒṗDfU$ṪḌ

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How it works

ŒṗDfU$ṪḌ  Main link. Argument: n (integer)

Œṗ        Find all integer partitions of n.
  D       Convert each integer in each partition to base 10.
     $    Combine the two links to the left into a chain.
    U     Upend; reverse all arrays of decimal digits.
   f      Filter the original array by the upended one.
      Ṫ   Take the last element of the filtered array.
          This selects  the lexicographically smallest decomposition of those with
          the minimal amount of palindromes.
       Ḍ  Undecimal; convert all arrays of decimal digits to integers.