Okla. Stat. tit. 60, § 60-299.3: Donees - Exercising power of appointment

A donee may exercise a power of appointment only by an

instrument executed with sufficient formalities to pass title to the

property covered by the power. When a power of appointment is

exercisable only by will, a donee may not exercise it by deed. When

a power of appointment is exercisable by deed, a donee may exercise

it by will.