SOLVED. brother and sister with powers fight against an evil yellowed eyed witch [s]

[Samantha]

Hello everyone. So I'm trying to remember the name of a book where there is two siblings, an older sister and a brother, where they both have powers. The sister can create anything by thinking it and the brother is able to erase an ability from being done again. At one point he's testing his abilities and so the sister creates a beautifully carved desk of her grandfathers that she remembers, with specific carvings and special drawers, with her mind power thing. Then he uses his power and she can't recreate that specific thing ever again.
Also there's another part where she is instructed to make a pb and j sandwich and she makes it but it tastes awful because she forgot to imagine the taste along with its appearance.
The final thing I remember is that the antagonist is this crazy witch lady that apparently has these terrifying yellow eyes and she's either leading or part of an army that's trying to destroy or take over something. Vague I know but that is all I have..
I read this book about 12 years ago and these parts are sticking with me vividly but no luck coming up with the title. Thanks in advance for your help.

[Ann aka Iftcan]

Was this a children's chapter, YA, NA or adult book Samantha?

[Samantha]

YA maybe

[Sue]

The Doomspell trilogy by Cliff McNish?

[Kris]

The Doomspell Trilogy (first book is The Doomspell) by Cliff McNish for Sue's suggestion.

[Samantha]

Oh my gosh that's it. Thank you so much!!