Nectarine up side down chiffon cake

i was going to make the cardinal slice this week but i messed up the buttercream last night, so i started to look for something easier to bake and voila - the nectarine up side down chiffon cake. this cake was adapted from "baking with Julia" book.
i got some white nectarines from japan town, they were so fragant - almost like a nectarine jolly rancher if there's such a thing.

on with the cake - the recipe called for 10" srping form round, 3" high. preheat oven at 350F

for the streusel:
75gr sliced almond - spread out on a jelly roll pan bake for 5-10 minutes until golden brown. let cool completely.
50gr dark brown sugar
50gr flour
60gr butter, cut in 1/4' cubes, chilled.
1 teaspoon ginger powder
1 teaspoon cinnamon powder

In the food proccessor bowl, add sugar, flour, cinnamon, ginger, pulse for 5 seconds to mix. add butter pulse for about 5-10 seconds to get crumbly texture. on a parchement line pan, spread out the crumbs and bake for about 15 minutes. set baked crumbs on cooling rack, add toasted almond immediately, toss well and spread out to let the streusel cool down completely, set aside.

for the fruit:
3-4 nectarines, i used 3 since the nectarines were large. cut into 8 slices per fruit vertically.
60 gr butter, slice into 4-5 slices
200 gr dark brown sugar

wrap bottom of spring form pan with foil to catch any dripping later. add butter to spring form pan, place spring form in oven until the butter just melt. add sugar, pack it down evenly. add nectarine slices, arrange in concentric circles, set aside.

for the cake:
4 yolks - about 65 gr
85gr safflower oil
85gr lemon juice

155gr flour
180gr sugar
1 teaspoon baking soda
1 teaspoon baking powder
1/4 teaspoon of salt
1 teaspoon extract optional, i used peach flavor.

6 eggwhites - about 200gr
90gr sugar
pinch cream of tartar
pinch of salt

whisk yolks, oil, lemon juice together until blend.
mix flour, 180gr sugar, baking soda, baking powder and salt well.
sift the flour mixture over yolk mixture in 2 portions, whisk to mix well. set aside.

beat eggwhites on low for 30 seconds, add salt beat until frothy. increase to medium speed, add cream of tartar beat until soft peaks, about 1 minutes.
add 90gr sugar in a small steady stream beat until all sugar is dissolved, about 2 minutes. increase to high speed, beat to stiff peaks, about 2 minutes.
fold 1/3 of meringue into yolk batter, fold gently with a flexible spatula until everything is incorporated. add batter back to the remaining meringue and fold gently until homogenous. the batter should not be deflated in volume.
pour 1/2 batter into fruit line pan, spread out evenly. sprinkle evenly with streusel, pour in the rest of the batter, smooth the top evenly. set spring form on a jelly roll pan and bake for about 50 minutes or until inserted toothpick comes out clean. set the whole thing on cooling rack and let it cool down for about 30 minutes before invert the cake on to a serving plate.

my note after tasting this cake. i really like the texture of this cake. personally, i would cut back on the sugar since i like things not too sweet. and second, if i make this again, i would caramelized the fruit seperately and bake the cake with streusel in a regular round pan instead of spring form. the fruit makes the bottom of the cake a bit soggy. and caramelized the fruit seperately is the only way to control the texture of the fruit, not over or under cooked. if so, it wouldn't be up side down cake but i imagine it would taste better.