Preheat your oven to 350°F (175°C). Gather your materials, including a 9-inch pie plate and the ingredients for the crust.

In a food processor, pulse the gingersnaps until they form fine crumbs. Transfer to a mixing bowl, add ground walnuts and brown sugar, then pour in the melted butter. Combine until the mixture resembles wet sand.

Press the crumb mixture into the bottom and up the sides of your pie plate, ensuring an even layer. Bake for 10-15 minutes until the crust is firm to touch and slightly darkened. Allow to cool completely.

In a saucepan, combine fresh cranberries with 2 cups of sugar and enough water to cover. Bring to a gentle simmer over medium heat for about 15 minutes, until the cranberries burst and release juices.

Blend the mixture until smooth using an immersion or regular blender. This will become a rich filling for your pie.

Return the cranberry puree to the saucepan. Whisk in eggs, egg yolks, kosher salt, lemon juice, and remaining sugar. Cook over medium heat, stirring constantly for about 10 minutes until it thickens noticeably.

Strain the cranberry curd through a fine mesh sieve into a bowl. Gradually stir in room temperature butter pieces until fully incorporated.

Pour the cranberry filling into the cooled gingersnap crust, spreading it evenly. Cover loosely with plastic wrap and chill in the refrigerator for at least 2 hours or until set.

Garnish with sugared cranberries and sprigs of fresh herbs before serving.