Preheat oven to 350°F (180°C). Spray a 13½x4¼-inch fluted removable-bottom tart pan with baking spray with flour.

For crust: In a medium bowl, stir together cookie crumbs, sugar, and salt.

In a small bowl, whisk together melted butter and egg yolk. Stir butter mixture into cookie crumb mixture until well combined. Press mixture into bottom and up sides of prepared pan.

Bake until fragrant, 15 to 20 minutes. Let cool for 30 minutes. Leave oven on.

For filling: Using a small offset spatula, spread Satsuma Marmalade in bottom of cooled prepared crust; freeze until cold, 10 to 15 minutes.

In a large bowl, whisk together condensed milk, satsuma zest and juice, egg yolks, vanilla, and salt until well combined. Spread onto marmalade in prepared crust. Using a wooden pick, pop any air bubbles on surface.

Bake until fragrant and edges of crust look dry, edges of filling are set, and center jiggles slightly, 20 to 25 minutes. Let cool completely in pan on a wire rack. Loosely cover and refrigerate until cold, at least 4 hours, or up to overnight.

Just before serving, remove from pan, and top with whipped cream. Garnish with Candied Satsuma Peels, if desired.

Peel and seed satsumas, reserving peels. In the work bowl of a food processor, process satsuma flesh and peels and lemon zest and juice until almost smooth, about 1 minute. (There should still be some small pieces remaining.)

In a medium saucepan, bring satsuma mixture to a boil over medium heat. Reduce heat to low, and simmer for 10 minutes. Stir in sugar and salt, and increase heat to medium-high; cook, stirring frequently, until mixture is thickened and an instant-read thermometer registers 210°F (98°C), 35 to 40 minutes. Remove from heat, and let cool completely. Refrigerate in an airtight container for up to 1 month.

Preheat oven to 250°F (130°C). Line a rimmed baking sheet with parchment paper; top with an ovenproof wire rack.

Peel satsumas, keeping peels in large pieces. Cut peels into 2x1/16-inch strips. Reserve satsuma flesh for another use.

In a large skillet, bring satsuma peel strips and 2 cups (480 grams) cold water to a low boil over medium heat. Reduce heat, and simmer, without stirring, for 10 minutes; drain.

Return satsuma peels to skillet; sprinkle 1 cup (200 grams) sugar onto peels. Pour remaining 1 cup (240 grams) cold water onto sugar; gently stir until combined. Bring to a boil over medium-low heat; reduce heat, and simmer for 15 minutes. Using a slotted spoon or tongs, carefully remove satsuma peels, and arrange in a single layer on prepared rack.

Bake for 30 minutes.

In a shallow dish, place remaining ¾ cup (150 grams) sugar. Dredge satsuma peels in sugar to fully coat. Return to rack; let stand until dry, at least 2 hours. Store in an airtight container for up to 1 week.