Step 1

Place a rack in middle of oven; preheat to 350°. Lightly grease a 13x9" baking dish with unsalted butter and dust with all-purpose flour, tapping out excess.

Step 2

Heat ¾ cup whole milk and 4 Tbsp. unsalted butter in a small saucepan over medium, stirring occasionally, until butter is melted, about 4 minutes. Remove from heat and let cool slightly.

Step 3

Beat 3 large eggs in the bowl of a stand mixer fitted with the whisk attachment on low speed until combined. Increase speed to medium and gradually add 1¼ cups (250 g) sugar; mix until combined. Increase speed to medium-high and beat until mixture is pale, glossy, and doubled in volume, about 3 minutes. Remove bowl from stand mixer and sift in 2 cups (250 g) all-purpose flour, 1½ tsp. baking powder, and ¾ tsp. Diamond Crystal or ½ tsp. Morton kosher salt. Using a rubber spatula, fold until flour is mostly incorporated. Add milk mixture and stir gently until just incorporated (don’t overmix). Scrape batter into prepared baking dish and smooth top if needed.

Step 4

Bake cake until top is golden brown and springs back when gently pressed, 25–30 minutes. Let cool in pan 15 minutes.

Step 5

While the cake is cooling, heat 3 cups whole milk, 1 tsp. saffron threads, and ¼ tsp. kosher salt in a medium saucepan over medium until steaming and creamy yellow in color. Remove from heat and stir in one 14-oz. can sweetened condensed milk and one 12-oz. can evaporated milk until smooth and combined. Set aside 1½ cups saffron milk for serving; chill until ready to use.

Step 6

Using a toothpick, poke holes in cake at 1" intervals. Pour remaining saffron milk evenly over cake. Chill cake, uncovered, at least 1 hour and up to 12 hours (4 hours is ideal).

Step 7

Meanwhile, beat 2 cups chilled heavy cream, 3 Tbsp. sugar, and ¼ tsp. kosher salt in the bowl of a stand mixer fitted with the whisk attachment on medium speed until soft peaks form, about 3 minutes. Cover and chill until ready to serve.

Step 8

Cut cake into 12 pieces and serve topped with 2 Tbsp. reserved saffron milk and a generous dollop of whipped cream. Scatter ¼ cup finely chopped raw pistachios over, dividing evenly.