Step 1: Prepare the Cake Batter

1. Preheat the oven to 350°F (175°C). Grease and line a 9×13-inch baking pan.
2. Sift together flour, baking powder, and salt. Set aside.
3. In a large bowl, cream butter and sugar until light and fluffy.
4. Add eggs one at a time, mixing well after each addition. Stir in vanilla extract.
5. Gradually add the dry ingredients, alternating with the milk. Mix until just combined.
6. Gently fold in the finely ground pistachios.

Step 2: Bake the Cake

1. Pour the batter into the prepared pan and smooth the top.
2. Bake for 30-35 minutes, or until a toothpick inserted in the center comes out clean.
3. Allow the cake to cool in the pan for 10 minutes before transferring it to a wire rack.

Step 3: Make the Milk Mixture

1. In a bowl, whisk together whole milk, condensed milk, evaporated milk, heavy cream, and pistachio paste.
2. Stir until well combined and smooth.

Step 4: Soak the Cake

1. Once the cake is completely cool, use a skewer or fork to poke holes all over the surface.
2. Slowly pour the milk mixture over the cake, allowing it to absorb fully.
3. Cover and refrigerate for at least 3 hours or overnight.

Step 5: Prepare the Whipped Topping

1. In a chilled mixing bowl, beat heavy cream, powdered sugar, and vanilla extract until stiff peaks form.
2. Spread the whipped cream evenly over the soaked cake.

Step 6: Garnish & Serve

1. Sprinkle chopped pistachios over the top for crunch.
2. Optional: Add rose petals or gold flakes for an elegant touch.
3. Serve chilled for the best texture and flavor.