La Tartine Gourmande: Recipes for an Inspired Life is perfect. The recipes remind me of Heidi Swanson's Super Natural Every Day but are a bit fussier for when you feel like a cooking project. I am often so visually overwhelmed by the parade of idyllic photos on Bea's blog that I click away instead of scrolling down to inspect the recipe. But in cookbook form, with one gorgeous full page photo per recipe, the photography is put to good use drawing your attention to the creative recipes. I love how her food is defined by unexpected flavor combinations instead of the absence of ingredients she avoids. Instead of a recipe for a gluten-free cake or muffins, she gives you strawberry, millet, almond cake with buttermilk or basil-zucchini muffins with comte cheese. So in spite of the fact that the format is what drew me in, this recommendation isn't just based on style preferences. Bea will expand your palette and maybe even inspire some kitchen experimentation. The recipes cover lunch and dinner as well as baking, but baking in particular with these recipes will require you to use some ingredients you probably haven't worked with before. It definitely won't duplicate the recipes in the cookbooks you already own.
Ripe: A Cook in the Orchard I estimate that Nigel Slater's tome on fruit has fifty pages devoted to just apple recipes (sweet and savory), but the basic recipes like apple crumble show you how to improve on traditional techniques to bring the flavor of those apples into focus. It's deep and wide.
P.S. Book links go to Amazon - I get some spare change if you buy something.