Yes, you can buy cake with Ethereum. There are a few ways to do this, and each has its own set of benefits and drawbacks.
The first way is to find a bakery that accepts Ethereum as payment. This can be tricky, as not many businesses are set up to accept cryptocurrency yet. However, there are a few out there, and the number is growing every day.
One advantage of this method is that you can use your Ethereum directly to purchase the cake, without having to go through an exchange or intermediary. However, the downside is that you may have to search around quite a bit to find a bakery that accept Ethereum, and even then there is no guarantee they will have the type of cake you want.
Another option is to use an exchange or intermediary that accepts Ethereum and converts it into fiat currency (like US dollars). This has the benefit of being able to use any type of cake you want, as most bakeries accept fiat currency.
However, the downside is that you will have to pay fees to the exchange or intermediary, and there is always the risk that the value of Ethereum could drop between the time you purchase it and when you actually use it to buy the cake.
So, can you buy cake with Ethereum? Yes! But it might not be as simple or straightforward as you would like.