Preheat oven to 350°F (180°C).

In the work bowl of a food processor, process chopped satsumas until almost puréed, about 30 seconds. (There should still be some small pieces remaining.)

In a medium bowl, whisk together flours, baking powder, and salt.

In the bowl of a stand mixer fitted with the whisk attachment, beat 2 cups (400 grams) sugar and eggs at medium-high speed until thick and pale, 5 to 7 minutes. With mixer on medium speed, add melted butter and vanilla, beating until combined. Add puréed satsuma, beating until fully combined. Add flour mixture, and beat at low speed just until combined, stopping to scrape bottom and sides of bowl.

Spray a 10-cup Bundt pan with bakingspray with flour. Pour batter into prepared pan.

Bake until top is golden brown and a wooden pick inserted near center comes out clean, about 1 hour, loosely covering with foil after 45 minutes of baking to prevent excess browning. Let cool in pan for 10 minutes.

Meanwhile, in a small saucepan, bring satsuma juice and remaining ¼ cup (50 grams) sugar to a boil over medium heat, whisking occasionally until sugar dissolves.

Invert cake onto a wire rack, and gently brush satsuma syrup all over cake. Let cool completely on a wire rack. Garnish with sliced almonds and Candied Satsuma Peels, if desired. Store in an airtight container for up to 3 days.