• Before You Start: This recipe is for my 9-inch (23 cm) round pan or 8-inch (20 cm) square pan. For a smaller pan, see the measurement in the blog post.
• Gather all the ingredients. Preheat the oven to 350°F (180ºC) and set the oven rack in the middle position. I highly encourage you to weigh your ingredients using a kitchen scale for this recipe. Click on the “Metric” button at the top of the recipe to convert the ingredient measurements to metric. If you‘re using a cup measurement, please follow the “fluff and sprinkle“ method: Fluff your flour with a spoon, sprinkle the flour into your measuring cup, and level it off. Otherwise, you may scoop more flour than you need.
  
• Crack 3 large eggs (50 g each w/o shell) in a small bowl (to avoid accidentally adding a broken egg shell into the batter). In another medium bowl, whisk together 1¼ cups all-purpose flour (plain flour), 1½ tsp baking powder, and 1 tsp Diamond Crystal kosher salt.
  
• Slice 6 plums in half by cutting the fruit around the pit. Hold the fruit and twist it to open.
  
• Remove the pits from the halves. Optionally, slice them into wedges. For peaches, coat them with lemon juice to prevent them from turning brown.
  
• Add 11 Tbsp unsalted butter to the bowl of an electric mixer fitted with the paddle attachment or beaters. Grease a 9-inch springform pan (both the sides and bottom) with the residual butter left on the wrapper.
  
• You can line the bottom of the cake pan with a parchment paper circle (optional). This will make it easier to remove the cake from the pan.
  
• Add ¾ cup sugar to the mixer bowl. Cream the butter and sugar until pale and fluffy, about 3 minutes.
  
• Add the eggs, one at a time, and beat on low speed until well combined.
  
• Using the silicone spatula, scrape down the sides of the bowl and add 1½ tsp almond extract.
  
• Gradually add the flour mixture and beat on low speed until smooth and combined.
  
• Scrape down the sides of the bowl with the spatula.
  
• Transfer the batter to the prepared pan and smooth the top with the spatula.
  
• Arrange the plums on top of the batter in a circular pattern, cut side down* or up to mostly cover the surface.

  * Cut-side down helps the plums stay juicy and creates a softer, moister crumb under each piece, while giving the cake a beautiful, golden top (my choice today).

  * Cut-side up gives the plums a rustic, caramelized look. As the juices bubble up, the fruit edges turn golden and slightly chewy.

  For wedges, fan them out on the cake batter.

  If you are using blueberries, mix them with 1 tsp of flour and lemon juice (If you use frozen blueberries, use them frozen). Spoon the berry mixture over the batter. The flour coating prevents the blueberries from sinking to the bottom of the cake.

  Nami's Tips: Gently press the plum halves or slices into the batter. They'll sink just the right amount as the cake bakes and rises.
  
• Sprinkle ¼ tsp ground cinnamon and 1½ tsp white sparkling sugar over the plums.
  
• Bake for 40 to 50 minutes (larger fruit needs a longer bake time), until the cake is golden on top and a toothpick inserted into the center comes out clean.
  
• Place the cake on a wire rack to cool. Run a butter knife along the outer edge of the cake to loosen it from the pan. Then, release and remove the sides of your springform pan, leaving the base in place.
  

To Serve

• Slice and serve at room temperature. You can also serve it with ice cream or whipped cream, if desired.
  

To Store

• Store the leftover cake, covered, at room temperature for up to 2 days, or refrigerate for up to 5 days.

  To freeze, let the cake cool completely. Wrap it tightly in plastic wrap or aluminum foil, then place it in a freezer bag. It will keep well for up to 3 months.

  Before serving, thaw the cake overnight at room temperature, or warm it in a 350ºF (180ºC) oven for 5–10 minutes.