• Preheat the oven to 350°F.

Prepare the dry ingredients:

• In a bowl, whisk together the flour, baking powder, baking soda, and salt until well combined. Set aside.

Make the cake batter:

• In another bowl, beat the softened butter and sugar together until light and fluffy. Add the eggs one at a time, mixing well after each addition. Stir in the vanilla bean seeds and vanilla paste.

Combine wet and dry ingredients:

• Gradually alternate adding the dry ingredients and the milk into the wet mixture, mixing until just combined.

Bake the cake:

• Divide the batter evenly between two prepared 9-inch cake pans. Bake for 25–30 minutes, or until the cakes are golden and spring back when lightly pressed.

Cool the cakes:

• Remove the cakes from the oven and turn them out onto cooling racks to cool completely.

Make the frosting:

• In a large bowl, beat the butter on high speed until light and fluffy. Add the pistachio pudding mix and vanilla extract, and blend until fully incorporated. Gradually add the powdered sugar, one cup at a time, mixing well between each addition. Once all the sugar is added, slowly pour in the milk until you reach your desired frosting consistency. Continue to beat on high for about 5 minutes to achieve a fluffy texture.

Assemble the cake:

• Place one layer of the cake on a turntable or cake stand. Spread about 1 cup of frosting in the center, leaving a ½-inch border from the edges. Top with the second layer of cake.

Frost the cake:

• Spread the remaining frosting over the top and sides of the cake, reserving about 1 cup of frosting for decoration.

Create texture on the frosting:

• To create a textured finish, use an offset spatula to gently press into the frosting at the bottom of the cake, spinning the cake as you go. Repeat this process in rows until you reach the top of the cake.

Decorate:

• Pipe the remaining frosting into large rose shapes on top of the cake. Garnish with chopped pistachios for a beautiful and flavorful finish.