If something is sugarier, it has more sugar in it and tastes sweeter.
Sugarier can make people think of sweet things like candy or desserts.
Examples:
The cake is sugarier than the bread.
I like my tea sugarier than yours.
She made the lemonade sugarier than before.
The sugarier the better, I always say!
Her smile was sugarier than the sweetest candy.
The sugarier the fruit, the happier I am.