Preheat oven to 350ºF, and position rack in the center of your oven
Set up a dry, angel food cake pan, or 10-inch tube pan with a removable bottom*. Select a pan that can be inverted, and identify a bottle that will support your pan in that position (you will invert the cake to cool, a large wine bottle should work well for this purpose)
Combine LF, GF flour, baking powder, xanthan gum (if needed), and salt in small bowl. Set aside
Beat 7 room temperature egg whites in the large bowl of your electric mixer with the whisk attachment, starting at low speed and increasing gently
Beat until the whites are foamy. Add cream of tartar, then increase speed to high
While eggs are beating, add the 1/2 cup of the sugar, 2 tablespoons at a time, until sugar dissolves and whites form stiff and glossy peaks, without scraping the sides of the bowl. Set aside
Using a separate bowl, with the flat paddle attachment, beat the 6 egg yolks until lemon colored. Gently add your remaining cup of sugar, 2 tablespoons at a time, until pale yellow and thick
Add oil, and mix until well incorporated
Add LF milk, and vanilla extract, and beat until just combined for about 30 seconds on medium speed
Add the flour mixture, and mix again on low speed, until smooth
Detach the bowl, and fold 1/3 of the beaten egg whites into the batter by hand, then fold the remaining whites in gently (you don’t want to let the air from the eggs deflate)
Pour batter into the prepared cake pan and place in center of preheated oven
Bake 45 -55 minutes until cake is slightly golden, the center springs back when touched, and a tester has only a few light crumbs
Allow to sit for 10 minutes, then invert cake to cool completely on your bottle
Invert cake in pan on your narrow-necked bottle, and cool completely while it is upside down
Remove from the bottle, place cake ‘right side up’ and loosen around the edges with a sharp knife. Then, carefully lift, and/or, flip the cake from the pan onto a serving plate
Serve with freshly whipped cream, or low-FODMAP Coconut Whipped Cream, and low-FODMAP berries (if you like, you may also cut the cake in half horizontally, and fill the middle with cream)
Notes
Although this recipe has not been lab tested, a single serving should be low-FODMAP based on the ingredients (using available FODMAP data at time of posting)
I always use Authentic Foods GF Classical Blend Flour, because of my bake-off contest!
You want the cake to ‘stick’ to your pan to keep it from falling. Do not use a non-stick pan, and do not grease your pan
If you avoid lactose, then pre-treat heavy cream with lactase drops 24 hours prior to whipping
Cream of tartar is a white powder, often found in the spice or baking section of grocery stores. It helps to stabilize egg whites, and also acts as a leavening agent