Spiced Almond Upside-Down Plum Cake

Ingredients:

Caramel and fruits

• 3/4 cup sugar
• 0.5 tsp coarse salt (optional)
• 600-700 g of firm ripe plums, cut into 1 cm slices (cut small ones in half)

Pie

• 1.5 cups premium flour
• 1/4 cup finely ground almonds
• 1 teaspoon baking powder
• 0.5 tsp ground allspice
• 0.5 tsp of soda
• 0.5 tsp ground cinnamon
• 0.5 tsp fine salt
• 1 cup of sugar
• 110 g unsalted butter at room temperature
• 2 large eggs
• 1 tsp vanilla extract
• 1 cup of sour milk/kefir or 3/4 cup of whole milk mixed with 1/4 cup of sour cream or Greek yogurt

Preparation:

1. Preheat oven to 190°C.
2. Caramel and fruits:
   
   In a 25cm ovenproof skillet, combine the sugar with 1.5 tablespoons of water until the mixture resembles wet sand. Heat over medium heat, stirring occasionally, until the sugar melts and turns light amber, about 5 minutes. Add salt if making salted caramel. Arrange the plums, cut side down, on top.
3. In a medium bowl, combine the flour, almonds, baking powder, allspice, baking soda, cinnamon, and salt. In a large bowl, beat the butter and sugar with a mixer on medium speed until light and fluffy, about 3 minutes. Add the eggs one at a time, beating after each addition, then add the vanilla extract. Reduce the mixer speed to low and add the flour mixture in three additions, alternating with the buttermilk. Knead until smooth.
4. Pour the batter over the fruit and spread it evenly. Bake until golden brown and a toothpick inserted into the center comes out clean, 35-50 minutes. Let rest for 15 minutes, then invert the pie onto a serving platter. Cool to room temperature and serve.