Yume-iro Pâtissière, Seiyuu Ka! Recommendations
Well, both have a girl who really isn't good at anything. They get really terrible grades, and at home their always in the shadow of their younger sister. When they go to a skills school to go into a career (YP is patissiere, and SK is voice actor) they get put into the advanced section, but after the first day everyone wonders why because they fail at everything! However, overtime they improve, and when they succeed in something, they do it REALLY well. Both girls have a lot of guys falling for them.
Whilst Seiyuu Ka is about voice acting, which is much different than baking, both female leads have the same determined personality. Also, did I mention that they both kinda suck at what they do, whether it be clumsiness or a bad voice holding them back?