Step 1: Orange Turkish Delight

1. Make sugar syrup: In a small saucepan, combine sugar, lemon juice, and enough water to total 180 mililiters. Boil over medium heat until it reaches 121°C (250°F), about 20 minutes.
2. Cornstarch mixture: Meanwhile, in a large saucepan, whisk together orange juice, cornstarch, and citric acid. Cook over medium heat, stirring, until very thick. Reduce heat to low while sugar syrup finishes.
3. Combine: Slowly pour the hot sugar syrup into the thickened orange juice mixture, stirring constantly. Once combined, raise heat to medium and simmer for 30 minutes, stirring often. Mixture should become glossy and very thick. Stir in orange bakery emulsion and food coloring (if using) at the end.
4. Cool and dry: Pour into an oiled parchment-lined or oiled plastic-wrapped pan similar in size to your cake pan. Refrigerate uncovered overnight to dry out.

Step 2: Orange Cake

1. Mix dry ingredients: In a bowl, whisk together flour, baking powder, baking soda, and salt.
2. Make citrus sugar: In another bowl, rub zest into sugar until fragrant and becomes a wet sand consistency.
3. Mix wet ingredients: In the citrus sugar, whisk in melted butter, oil, eggs, vanilla, lemon juice, orange juice, milk, and sour cream.
4. Combine dry and wet, then rest: Gently fold in dry ingredients until just combined. Do not overmix. Rest the batter for 20–30 minutes at room temperature. Preheat oven to 175°C (350°F). Line a half-sheet pan (approx. 23x33 cm / 9x13 inches) with parchment and lightly grease.
5. Bake: Pour in the batter and bake for 25 minutes or until a toothpick inserted in the center comes out clean.
6. Chill: Cool completely on a cooling rack before adding the Turkish delight.

Step 3: Assemble

1. Prepare cake: Trim the cake top if it is uneven. This is usually not necessary for this recipe.
2. Prepare Turkish delight: Loosen the edges of the chilled Turkish delight using an oiled knife off the parchment paper. Invert the parchment paper onto cake and peel off the paper.
3. Trim edges if needed to match the cake size. Chill briefly while tempering chocolate.

Step 4: Chocolate Coating

1. Temper chocolate: Melt chocolate gently (in microwave at 30-second intervals, stirring). Heat to 45°C (113°F), cool to 28–29°C (82–84°F), then reheat slightly to 31°C (88°F) for perfect tempering.
2. Add chocolate and slice: Pour about 80% of the tempered chocolate* over the cake, spreading in a thin, even layer. Slice cleanly with a hot knife before the chocolate has a time to set.
3. Store in a cake box for 4-5 days. Keeps a little longer in the refrigerator but it's possible that the chocolate starts to bloom (get white streaks and spots, but it doesn't affect the taste).