Para el desayuno, me gusta mezclar ciruela y frambuesa con yogur natural.

Because gustar works differently from English to like. In Spanish, the thing you like is the grammatical subject, and me means to me.

So the structure is roughly:

• Me gusta X = X is pleasing to me

Here, X is mezclar ciruela y frambuesa con yogur natural.

Also, yo gusto usually does not mean I like. It would more likely mean I am pleasing / attractive, which is a different idea.

Because the thing being liked is the whole action mezclar ciruela y frambuesa con yogur natural. An infinitive phrase like mezclar... counts as a singular idea in Spanish.

So:

• Me gusta mezclar... = I like mixing...

But if the things you liked were the nouns themselves, you would use plural:

• Me gustan las ciruelas y las frambuesas.

It sets the context: for breakfast.

It tells you when or for what occasion the speaker likes doing this. In English, it is similar to saying:

• For breakfast, I like...

Other natural options are:

• En el desayuno... = At breakfast / during breakfast
• Para desayunar... = For breakfast / to have for breakfast

All are possible, but they are not exactly identical in nuance. Para el desayuno sounds like as a breakfast choice.

Because Para el desayuno has been moved to the front as an introductory phrase. The comma marks a small pause.

So this is like English:

• For breakfast, I like...

You could also write it without the comma in informal contexts, but the comma is very normal and helpful here.

Spanish often leaves out subject pronouns when they are not needed. The verb and the context usually make the subject clear.

So me gusta already naturally means I like here. Adding yo would usually give extra emphasis or contrast:

• Yo prefiero tostadas, pero ella no.
• A mí me gusta esto, pero a él no.

In a neutral sentence, leaving out yo is the normal choice.

In everyday speech, many native speakers would more naturally say ciruelas y frambuesas if they mean actual pieces of fruit.

So a more natural version would often be:

• Me gusta mezclar ciruelas y frambuesas con yogur natural.

The singular version is understandable, but it can sound a bit generic or recipe-like, almost like naming ingredients or flavours rather than individual fruits.

Spanish often omits articles with food and ingredients in general statements, especially after verbs like comer, beber, or mezclar.

That said, there is a small difference in how natural each noun sounds without an article:

• con yogur natural sounds completely natural
• ciruela y frambuesa is understandable, but many speakers would prefer ciruelas y frambuesas in normal conversation

So the article omission itself is not strange, but with countable fruits, plural nouns often sound more everyday.

In Spain, yogur natural means plain yogurt: yogurt without added fruit flavour like strawberry or peach.

It does not usually mean organic or all-natural in the English marketing sense. If you want to say organic yogurt, you would normally use something like:

• yogur ecológico
• yogur bio (depending on packaging/branding)

They are:

• la ciruela — feminine
• la frambuesa — feminine
• el yogur — masculine

A useful detail: natural has the same form in masculine and feminine singular, so you do not see a gender change there.

• yogur natural
• fruta natural

But in the plural, it changes:

• yogures naturales

Yes. Spanish word order is flexible, especially with introductory phrases.

For example, you could also say:

• Me gusta mezclar ciruelas y frambuesas con yogur natural para el desayuno.
• Para desayunar, me gusta mezclar ciruelas y frambuesas con yogur natural.

Putting Para el desayuno first gives it a little more emphasis, as the topic or setting of the sentence.

It is understandable, but many native speakers would probably make it sound a bit more natural by using the plural fruit names.

For example:

• Para desayunar, me gusta mezclar ciruelas y frambuesas con yogur natural.
• En el desayuno, me gusta mezclar ciruelas y frambuesas con yogur natural.

So the original sentence is fine for learning, but ciruelas y frambuesas would usually sound more natural in everyday Spanish.