Step 1: Line a 10” by 15” baking tray with parchment paper.
Step 2: Sift all-purpose flour and hojicha powder together. Add milk and butter to a small cup, melt, and keep warm.
Step 3: Preheat oven to 350°F.
Step 4: In a large bowl, mix eggs and granulated sugar together with an electric mixer until just combined. Make a bain marie by putting that bowl over another bowl filled with hot water, then beat contents with an electric hand mixer at high speed. When the sugar dissolves, remove from the bain marie and keep mixing until light and fluffy.
Step 5: Add sifted ingredients to the mixture and incorporate well with a spatula. Then add the butter and milk mixture, stirring gently until batter is light and well-combined.
Step 6: Transfer cake batter into the 10” by 15” baking tray and smooth the top with a spatula. Tap the tray against the counter to remove air bubbles.
Step 7: Bake cake at 350°F for approximately 12 minutes, or until top is dry and cake is springy to the touch. Remove tray from oven and gently tap the tray onto the counter to help the cake release. Transfer to a cooling rack with the parchment side down.
Step 8: To make the hojicha whipped cream, add hojicha powder and sugar to heavy whipping cream in a large bowl. Whisk until soft peaks form.
Step 9: Measure a new piece of parchment paper then carefully flip the cake onto it, bottom facing up to remove the old parchment paper. Spread ¾ of the hojicha whipped cream over the cake’s surface, leaving a 1” border around the edge of the cake. Using the parchment paper, roll the cake up with the filling on the inside. Seam side down, place in refrigerator to chill for 1 to 2 hours.
Step 10: Once chilled, cut about 2” of the cake off with a serrated knife on a slight diagonal. Using the hojicha cream, attach this piece to the larger piece. Spread remaining hojicha whipped cream on top of the cake evenly, then use a fork to create the bark-like patterns. Decorate with your favorite fruit and then sprinkle hojicha powder or powdered sugar on top if desired.
Step 11: Keep the cake refrigerated until it’s time to serve. The hojicha whipped cream may melt if left out for too long.