Testing - Financiers

My sources:
http://www.seriouseats.com/recipes/2012/05/blueberry-financiers-recipe.html
http://www.joyofbaking.com/Financiers.html
http://www.epicurious.com/recipes/food/views/Almond-Cakes-101802
http://www.chow.com/recipes/28323-financiers
http://www.epicetoutlacuisinededany.fr/2015/03/fianciers-au-safran.html

1 - First attempt very good, but the bottoms brown far too quickly. Not owning Financier molds, I used those plasicky mini muffin molds, on a metal cookie sheet in the RV oven which tends to cook from below too hot... so many variables! However, if I can get the baking down right, I think the actual mix is good as it is.
2 -  Delicious little chewy cakes but needing some tweaking. I made them in a non-stick muffin tin, and they didn't stick, but they weren't attractive and the bottoms started to burn. I used the alternate baking temperatures (450F for 7, 400 for 7, oven off for 7) because I'd just baked some of my Wonder Bread and wanted to conserve energy by just using the existing temperature. Now, I don't know if the temperature was too high OR if the muffin tins were too small OR not full enough (I made 12 instead of 10) OR if they were just in there too long. I also did not refrigerate the mixture for an hour, which I'd like to try.
3 - Baked another version with wheat flour instead of arrowroot (I didn't have access to my arrowroot flour so I substituted) at Deb Morrison's. I baked them for 14 minutes but I could have gone the whole 15 and maybe a bit more. I don't know if it was the different oven or the wheat flour that prevented burning. They came out more custardy on the inside. And they are too sweet... come to think of it I didn't have powdered sugar so I used regular granulated and that may gave increased the sweetness?

4 - The temperature continues to be a challenge, and I'm trying something new - start the temp to 425, but to cook the cakes, I'll reduce the temp to 350 for 20 minutes. Then we'll see. Fingers crossed. https://www.cuisinedaubery.com/recipe/financiers-cookies/

And I just discovered that, unlike ghee, browned butter keeps the caramelized milk solids mixed in with the butter fat for extra flavor. https://www.abeautifulplate.com/clarified-butter-ghee-and-brown-butter/

Finally, after they've cooled completely, they get, I don't know, they stick to your teeth. That might be the arrowroot, but I wonder if leaving them in the oven until they brown at least around the edges would be better. Oh, I used the small muffin molds Randy gave us.

1 cup ground almonds

1/2 cup arrowroot flour

1 3/4 cup powdered sugar

1/2 tsp. salt

6 large egg whites

1 teaspoon pure vanilla extract

3/4+ cup unsalted butter, browned (use leftovers to butter tins)
1 cup of fresh or frozen berries (optional)
A pinch of cardamom (optional)
Fresh vanilla seeds from 1 pod (optional)
The zest of 1/2 a lemon (optional)

1. Before starting the cookies, brown the butter. To brown butter, put the butter in a pot and melt with medium-high heat. The butter will start to froth and making crackling sounds. When the frothing stops and the crackling slows, check that the milk solids, which have separated and settled to the bottom. The foam will eventually subside, small bubbles will form, and the milk solids will begin to brown. Reduce the heat to low and swirl the pan until the butter becomes fragrant (nutty) and a light amber in colour. Remove immediately from the heat source - this stage is quite quick when it comes, so vigilance is crucial to avoid burning the milk solids. Allow the butter to cool while mixing the rest of the ingredients.
2. Grease the baking pan (either mini muffin tins or, if you're fortunate, rectangular financier forms).
3. Mix together the ground almonds, the flour, the sugar, and the salt until combined.
4. Make a well in the bowl and add the egg whites, the vanilla and the butter. Whisk vigorously.
5. Wrap and put in the refrigerator to rest for an hour and up to 72 hours.
6. Adjust the oven rack to the middle position and preheat the oven to 425F 450F.
7. Fill each tin with the batter, almost to the top.
8. When you put the filled tin the oven, reduce the temperature to 350F. Bake until the financier just begin to rise, (if adding fruit, take out after 4 minutes of baking and add the fruit on top. Otherwise, leave in for...) about 7 minutes; reduce the temperature to 400F and bake until the Financiers have become golden brown around the edges and are springy to the touch, about 15 (20) another 7 minutes. Turn off the oven and leave them in the oven for about 10 minutes more. Allow to cool an additional 10 minutes before unmolding them.