Expression and い adjective
あまい
甘いケーキと美味しいワインを買って、うちに招待すれば、必ず友達を作れるよ。
My sure-fire way to make friends is to buy some sweet cake and good wine and invite them over.
This is a single kanji with an い on the end, meaning you know it's probably an adjective. What's the adjective form of sweet? It's sweet.
The reading is the same as the one you learned with the kanji.