Quiero prepararles un desayuno con fruta a mis padres.

Yes, they refer to the same people, and that is completely normal in Spanish.

This is called clitic doubling:

• les = the indirect object pronoun
• a mis padres = the full indirect object phrase

So:

• Quiero prepararles un desayuno...
• Quiero preparar un desayuno a mis padres...

In natural Spanish, especially with people, it is very common to use both:

• Quiero prepararles un desayuno a mis padres.

The pronoun les helps the sentence sound more natural and clearly marks my parents as the people receiving the breakfast.

Because my parents are the indirect object here, not the direct object.

In this sentence:

• un desayuno = the thing being prepared → direct object
• a mis padres = the people receiving it → indirect object

Spanish indirect object pronouns are:

• me
• te
• le
• nos
• os
• les

Since mis padres is plural, the correct pronoun is les.

So:

• les = to them / for them

Not:

• los/las, which would refer to a direct object such as them

Because with verbs like preparar, Spanish often expresses the person who benefits or receives something as an indirect object with a, not with para.

So Spanish thinks more like:

• I want to prepare them a breakfast rather than
• I want to prepare a breakfast for them

That is why you get:

• prepararles un desayuno a mis padres

You may sometimes see para mis padres in other contexts, but here a mis padres is the standard way to mark the indirect object.

You may hear sentences without the pronoun, but in standard, natural Spanish, especially with a person as the indirect object, les is strongly preferred.

So the more natural version is:

• Quiero prepararles un desayuno con fruta a mis padres.

Without les, the sentence is understandable, but it sounds less natural to many speakers.

Because preparar is an infinitive, and in Spanish object pronouns can be attached to an infinitive.

So these are both possible:

• Quiero prepararles un desayuno...
• Les quiero preparar un desayuno...

Both mean the same thing.

This is very common with structures like:

• quiero decirte
• te quiero decir
• voy a comprarlo
• lo voy a comprar

So prepararles is just preparar + les.

Yes. Spanish allows some flexibility.

All of these are possible:

• Quiero prepararles un desayuno con fruta a mis padres.
• Les quiero preparar un desayuno con fruta a mis padres.
• A mis padres les quiero preparar un desayuno con fruta.

The meaning stays basically the same, but the emphasis can shift:

• A mis padres... puts extra focus on my parents
• Les quiero preparar... sounds very natural in conversation
• Quiero prepararles... is also completely natural

Because here desayuno means a breakfast as a countable meal.

Spanish often uses an article where English may or may not:

• preparar un desayuno = to prepare a breakfast

If you said just preparar desayuno, it would sound incomplete or unnatural in this sentence.

So:

• un desayuno = one breakfast / a breakfast

Fruta is being used here as a general, uncountable noun meaning fruit in general.

So:

• con fruta = with fruit

This is very natural when talking about ingredients or food in a general sense.

Compare:

• un desayuno con fruta = a breakfast with fruit
• un desayuno con la fruta que compré ayer = a breakfast with the fruit I bought yesterday

You would use la fruta if you meant specific fruit already known in the conversation.

Yes, hacer is also possible in many contexts.

• preparar = to prepare
• hacer = to make

So these are both natural:

• Quiero prepararles un desayuno...
• Quiero hacerles un desayuno...

Preparar can sound a little more like get ready / put together, while hacer is a very common general verb for make.

In this sentence, preparar is perfectly natural.

Yes. Mis padres normally means my parents as a pair: mother and father.

• mi padre = my father
• mi madre = my mother
• mis padres = my parents

So the sentence means the speaker wants to prepare breakfast for both of them.

It describes un desayuno.

So the meaning is:

• a breakfast with fruit

Not:

• my parents with fruit

Spanish word order makes that clear here:

• prepararles un desayuno con fruta a mis padres

The phrase con fruta is naturally understood as part of un desayuno.