Creating Decadent Irresistible Pistachio Cream Cookies is simple when you follow these steps:

1. Preheat the Oven: Start by preheating your oven to 350°F (175°C) and line baking sheets with parchment paper.
2. Cream Butter and Sugars: In a large bowl, beat the softened butter, granulated sugar, and brown sugar until creamy and smooth.
3. Add Eggs and Vanilla: Mix in the eggs one at a time, followed by the vanilla extract until well combined.
4. Combine Dry Ingredients: In another bowl, whisk together the flour, baking soda, and salt.
5. Mix Dry and Wet Ingredients: Gradually add the dry mixture into the wet ingredients while mixing until just combined. Do not overmix.
6. Fold in Pistachios: Gently fold in the finely chopped pistachios and white chocolate chips if you choose to add them.
7. Shape the Cookies: Scoop tablespoon-sized portions of dough onto the prepared baking sheets, leaving space in between for spreading.
8. Create a Well for Filling: Before baking, make a small well in the center of each cookie with your thumb or the back of a spoon.
9. Bake: Place in the oven for 10-12 minutes, or until the edges are lightly golden.
10. Fill with Pistachio Cream: Once out of the oven, allow cookies to cool for a few minutes. Then, spoon pistachio cream into each well.
11. Cool Completely: Transfer cookies to a wire rack to cool completely.

These simple steps will guide you to create a batch of cookies that are truly decadent.