Learn Italian: Che panorama mozzafiato! È magnifico! - What a breathtaking panorama! It is magnificent!

In English, we say "What a...", but in Italian exclamations, you never use an indefinite article like un or una after Che. You simply put Che directly in front of the noun or noun phrase.

Could I use Quanto instead of Che in this sentence?

Not in this exact structure. Che is used directly before nouns (like Che panorama!). Quanto is used to mean "How" or "How much" and usually goes with verbs or adjectives, such as Quanto è magnifico! (How magnificent it is!).

How does the word mozzafiato work?

It is a compound adjective formed by combining mozza (cuts off) and fiato (breath). Because it is built from a verb and a noun, it is invariable. This means its ending never changes to match gender or number, so it stays exactly the same whether you are describing one masculine panorama or several feminine views.

Since panorama ends in -a, shouldn't the adjective be magnifica?

Panorama is actually a masculine noun. Many Italian words of Greek origin that end in -ma (like il problema, il sistema, and il clima) are masculine. Because the noun is masculine, the adjective describing it must be the masculine magnifico.