Loquat Upside-down Tassajara Gingerbread Cake

EPIC. Andrew turned 30 recently, and my advisor had a BBQ to welcome a student who will start in the fall, so brought a birthday cake to the BBQ. There are a ton of ripe loquats in the garden, so went looking for a recipe. This lady made a loquat upside down cake that looked amazing so I wanted to do that, but used the gingerbread cake from the Tassajara Bread Book instead of her cake, doubling the recipe to make a birthday-sized cake. The only thing I'd change is I only had 27 loquats on hand when I was baking it, it needed more, maybe double that. But otherwise it was great. Amazing with some freshly whipped Straus cream.

Loquat upside-down Tassajara gingerbread cake:
more than 27 ripe loquats, halved and pits removed
1 stick butter
6 oz sugar

~1 lb (4 1/2 C) sifted whole wheat flour
1 T baking powder
1 t sea salt
1 t soda
1 t ground cloves
2 t powdered mustard
2 t ginger
2 t cinnamon
1 c oil
2 c molasses
2 eggs
2 c hot water

350 oven. butter and sugar in a 13x9 pyrex pan throw it in the oven for 5-10 min till butter and sugar are happy. Lay loquats cut side down on the mixture.
Sift together flour, baking powder, salt.
Mix soda, and spices into oil. Put into a bowl, add beaten egg, then mix in molasses.
Add flour mixture and hot water to wet ingredients, alternating as you go. Beat well.
Pour over loquats.
350 45 min.