Question

how many / much sugar is needed to bake the cake

Answer 1

much, many is often used where there could be a set numerical value, much is where there is no set value but only quantity. you can't say, "there is many sugar" it's a quantity so much use should be used here.

Answer 2

YO BUDDY

Your answer-

How much sugar is needed to bake the cake.

Because Much is used for uncountable noun
(Sugar is uncountable noun)

HAVE A COOL DAY BUDDY