Preheat your oven to 425F/220C. Brown your butter in a small saucepan and set it aside.
In a bowl, whisk together all the ingredients (yes it’s as simple as that!), then pour in the brown butter and slowly whisk it in.
For your spices, this is where you can customize - add what you like according to your fruit (if you’re adding it), and how much you like (a tbsp is too much ;-)).
For your fruit, don’t using something with a high water content (think juicy pears or peaches) or your cake won’t cook. Instead use something that’s a little underripe or berries. Slice thin pieces of fruit to put on top, or place whole raspberries or other berries. No need to defrost if you’re using frozen.
After you put the financiers in the oven, lower the temp to 350F/170C and bake until done! This will depend on your mold but between 10-20 mins (or more!). Look for golden brown, pulling away from the side and springing back.