Word meaning "far greater than required or necessary"

Solution 1:

The word I immediately thought of, which sounds similar to overt, is overkill:

[Merriam-Webster]
2 : an excess of something (such as a quantity or an action) beyond what is required or suitable for a particular purpose
    // publicity overkill
    // an overkill in weaponry

In describing the situation in the question, you might way the following:

Buying 25 apples for a pie is overkill.

It has a more literal sense, but is often used in this figurative sense too.

Solution 2:

OED

excessive (adjective)

2. Of qualities, states, actions, magnitudes, etc.

b. Exceeding what is right, proportionate, or desirable; immoderate, inordinate, extravagant.

1875 B. Jowett in tr. Plato Dialogues (ed. 2) III. 681 A single night of excessive rain..left the rock of the Acropolis bare.

Merriam Webster

excessive (adjective): exceeding what is usual, proper, necessary, or normal

Collins:

excessive (adjective)

1 (adjective) in the sense of immoderate: The length of the prison sentence was excessive considering the nature of the crime.

Solution 3:

Those apples are surplus or superfluous.

Surplus (adjective): More than what is needed or used; excess. [Lexico]

Superfluous (adjective): Unnecessary, especially through being more than enough. [Lexico]