Preheat your oven to 350°F (175°C) and line a 10x15 jelly roll pan with parchment paper.

Whip egg whites on high speed until stiff peaks form, about 3–5 minutes. Set aside.

Cream egg yolks with brown sugar, granulated sugar, and vanilla extract until light and creamy, about 2–3 minutes.

Combine flour, baking powder, spices, and salt in a bowl, then gradually add to wet mixture with yogurt and molasses until smooth.

Fold the whipped egg whites into the batter carefully to maintain airiness.

Spread the batter evenly in the prepared pan and bake for about 10 minutes, until the cake springs back when lightly touched.

Sprinkle a clean kitchen towel with powdered sugar and carefully turn the hot cake onto it. Roll the cake while it's hot and let it cool for 1–2 hours.

Prepare sugared cranberries by dunking fresh cranberries in simple syrup and then rolling them in sugar; let dry on a wire rack.

Unroll the cooled cake and spread the mascarpone filling evenly across the surface. Roll back into a log shape.

Wrap the cake in plastic wrap and refrigerate for 30 minutes to 1 hour to allow flavors to meld.

Make meringue frosting by whisking egg whites and sugar over a double boiler until warm, then whip until stiff peaks form.

Cover the chilled cake with meringue frosting and garnish with sugared cranberries and fresh rosemary.