Plum Upside-Down Cake (in Ramekins, or Single Cake)

Prunes

By Cat, Jun 2014 (Photo, right, from Wikimedia Commons)

See also: 1. Pear Upside-Down Cake; 2. Cakes & Tortes Menu

NOTE: The ingredients of this and the Pear upside-down cake recipes are similar, but the original Fine Cooking recipe amounts (after converting to same 10″ round cake size) differ: the pear recipe used ¼ cup more flour and ¼ cup less butter than the plum recipe. My adaptations level these differences; Dec 2016 testing of pear recipe found a major error in my adaptations regarding the amount of butter; I’ve updated both recipes accordingly, but will need to test again.

Two years ago, I added an Italian Prune to my yard; it grows small, dark plums with wonderfully sweet purple flesh, and would be perfect for this recipe (used fresh, not dried). I like the idea of individual cakes made in ramekins or custard cups, but you could make this as one larger single cake (9″ size).

There are many different plum or prune varieties you could use, but if you want to make the individual cakes, you would do well to select small ones. Check out Michigan Plums (2) for listing and photos of many varieties of Asian and European plums. See also Canadian Living’s Plum Primer (3).

Plum Upside-down Cake

I’ve adapted this recipe from Fine Cooking (1). The original recipe calls for cake flour, which is a white flour; I prefer to use part whole wheat pastry flour (pre-soaked in sour milk or buttermilk) and part unbleached white flour. Cake flour, like pastry flour, is lower in protein than all-purpose flour. Cake flour is also more finely ground, but unless it is unbleached, it is treated with even more toxic bleaching agents than all-purpose flour. In my experience, pastry flour works quite well for upside down cake.

Other options:

• Joy the Baker (4) offers a ‘recipe’ to make your own cake flour using all purpose flour (I’d use unbleached) and corn starch (make sure it is Organic, to avoid GMOs; tapioca starch can also be used but use 2 Tbsp tapioca starch for each 1 Tbsp corn starch in the method). This method requires a lot of sifting to aerate the flour.
• King Arthur’s unbleached cake flour blend (5)
• Unbleached pastry flour (such as Bob’s Red Mill or King Arthur)

For those who need to minimize dietary sugars, I provide an option to sweeten the cake batter with a mix of sugar and stevia instead of all-sugar.

Makes 8 individual cakes to serve 8, or a single cake to serve 8 – 10.

Equipment:

• medium mixing bowl
• bakers parchment or waxed paper
• large mixing bowl
• 8 each 8-oz (1 cup) ramekins, or one 10″ round cake pan
• electric mixer
• rimmed baking sheet (if making ramekins)

Ingredients:

NOTE: recipe uses totals of: 1 ¼ cup or 2 ½ sticks butter (2 sticks for batter and ½ stick for fruit mix); 1 ¾ cup sugar or equivalent; ½ cup buttermilk; 1 ½ – 1 ¾ cup flour; and 2 large eggs

• Presoak (Day before baking)
• 1 ¼ cups whole wheat pastry flour (soft wheat)
• 3 Tbsp real butter, melted
• ¾ – 1 cup buttermilk, or clabbered milk (add 1 Tbsp lemon juice to milk and let rest at room temperature until it thickens); [original recipe had ½ cup] start with ¾ cup and increase if mixture is too thick
• Baking day: plums
• 4 Tbsp real butter (½ stick) [original recipe had ¾ cup butter in plum mix]
• ¾ cup Rapadura or white/brown cane sugar (or ¼ cup sugar plus ⅛ – ¼ tsp stevia extract powder)
• 6 – 10 plums (depending on size), ripe but firm, pitted and sliced in wedges about ⅛” thick (for ramekins); can be thicker if making one cake
•  Baking day: cake batter
• Presoak mix (flour and buttermilk; see above)
• 1 orange (for grated zest)
• ¼ cup unbleached pastry flour or unbleached all-purpose flour
• 1 tsp aluminum-free baking powder
• ¼ tsp baking soda
• ½ tsp ground cinnamon
• ¼ tsp unrefined sea salt
• 5 Tbsp real butter, room temp
• 1 cup Rapadura or white cane sugar (or 2 Tbsp Rapadura/white cane sugar plus scant ½ tsp stevia extract powder)
• 2 large eggs at room temperature
• 2 tsp real vanilla extract

Method:

1. Presoak (Day before baking): Using medium bowl, cut butter into 1 ¼ cups flour until it resembles oatmeal. Stir in ¾ cup (12 Tbsp) buttermilk to combine; add remaining 4 Tbsp if batter is too thick to stir. Add more flour, 1 Tbsp at a time, if too thin.
2. Press oiled parchment or waxed paper against the surface and cover bowl with a towel. Let rest on counter overnight.
3. Plums (Baking day): Wash plums, then slice into ⅛” thick wedges (if using ramekins) or thicker wedges if using cake pan.
4. If using stevia, mix it with the smaller amount of sugar in a small bowl with a whisk; you want stevia to be evenly distributed through the sugar
5. Lightly butter ramekins or cake pan.
6. Melt butter and divide it between the ramekins (or pour into cake pan). Sprinkle sugar (or sugar-stevia mix) over butter, then add plum wedges. If using cake pan, arrange the wedges in a swirl or spiral pattern.
7. Cake (Baking day): Pre-heat the oven to 350°F.
8. Sift flour, baking powder, baking soda, cinnamon, salt and stevia (if using) into mixing bowl.
9. Grate zest from orange; save orange meat and juice for another use.
10. Cream butter, sugar and orange zest until well mixed (using electric mixer); mix in eggs and vanilla extract, to combine. Stir in pre-soak mixture.
11. Divide batter among ramekins on top of the plums; or scoop all batter into cake pan, on top of plums, and level with spatula.
12. Arrange ramekins on rimmed baking sheet and place in oven; or place cake pan in oven. Bake until cake(s) are firm to the touch and juices are bubbling, rotating baking sheet or cake pan midway through baking to ensure even cooking. The ramekins will bake about 35 – 40 minutes; single 10″ cake will bake 45 – 55 minutes minutes. Insert toothpick to test doneness; plum juices will moisten the toothpick, but no batter should stick.
13. Remove to rack to cool to ‘warm’. Run a knife blade around inside edge of each ramekin or the cake pan. Invert onto a serving plate, and gently lift off the ramekins/pan.
14. Serve with Whipped Cream or vanilla ice cream. It’s best to make your own ice cream, as commercial ice creams use many questionable ingredients, including artificial and so-called natural flavors or coloring.
15. If you made the cakes well ahead of serving time, reheat (in their ramekins or cake pan) on rimmed baking sheet in 350°F oven for 2 – 5 minutes.
16. References
17. Fine Cooking recipe (finecooking.com/recipes/plum-upside-down-cake.aspx)
18. Michigan Plums: varieties (michiganplum.org/plum-variety-descriptions)
19. Canadian Living: plum primer (canadianliving.com/food/cooking_school/plum_primer.php)
20. Joy the Baker: How to Make Cake Flour (joythebaker.com/2009/09/how-to-make-cake-flour)
21. King Arthur’s unbleached cake flour blend (kingarthurflour.com/shop/items/unbleached-cake-flour-blend)