Pancake "4 flavors" on a baking sheet

Ingredients:

• 2 and 3/4 cups of sour milk or kefir
• 2 large eggs, beaten
• 1.5 tsp coarse salt
• 1.5 tsp vanilla extract
• 1/3 tbsp. + 1-2 tsp. granulated sugar
• 2 and 3/4 cups flour
• 1 tbsp baking powder
• 1.5 tsp of baking soda
• 4 tbsp (60 g) butter, melted
• 2 tbsp. strawberry jam, preferably seedless, warm
• 0.5 cup thinly sliced ​​strawberries
• 0.5 cup chocolate chips
• 1 banana, halved crosswise and thinly sliced ​​lengthwise
• 2 tbsp. l. brown sugar
• 1 teaspoon ground cinnamon
• 3 tablespoons powdered sugar
• Maple syrup and whipped cream, for serving

Preparation:

1. Position a rack in the middle of the oven and preheat to 260°C (400°F). In a large bowl, combine the buttermilk, eggs, salt, vanilla, and 1/3 cup granulated sugar. In another large bowl, whisk together the flour, baking powder, and baking soda until evenly distributed. Using a rubber spatula, fold the liquid mixture into the flour mixture and knead until a dough forms (it's okay if some lumps remain). Pour 2 tablespoons of the dough into a small bowl.
2. Grease a 45x32 cm (18x13 in) springform pan with 2 tablespoons (30 g) of butter and pour in the batter. Use a spatula to smooth the surface. Tap the pan on the counter a few times to even out the batter.
3. Stir the warmed jam in a small bowl until it becomes more fluid. Mentally divide the batter in the pan into four sections (2 at the top and 2 at the bottom). Spoon 1 teaspoon of jam onto the surface of each section. You should see red dots of jam on the batter. Use a toothpick or small skewer to draw through these dots to create a marbled pattern. Arrange the strawberry slices on top.
4. Sprinkle the second section of dough with chocolate chips. Arrange banana slices in a herringbone pattern on the surface of the third section and sprinkle with the remaining 1-2 teaspoons of white sugar.
5. In a small bowl, combine the brown sugar, cinnamon, and reserved dough and spoon it, 1 teaspoon at a time, onto the remaining dough. You should see a few brown spots on the surface of the dough. Using another toothpick or wooden skewer, run a skewer over these spots to create a marbled pattern.
6. Place the pan in the preheated oven and immediately reduce the temperature to 200°C. Bake, rotating the pan halfway through, until golden brown. A tester inserted into the center of the pancake should come out clean, 18-23 minutes.
7. Brush the pancake with the remaining 2 tablespoons (30 g) butter and let cool for 15 minutes before slicing. In a small bowl, combine the powdered sugar with 1 teaspoon of water and drizzle the glaze over the browned portion of the pancake.
8. Serve the pancake with maple syrup and whipped cream.