If using store‑bought crust, optionally par‑bake: chill crust, line with parchment or foil, fill with pie weights or dried beans. Bake at 375 °F for ~10 min, remove weights, bake another ~5–10 min until edges are lightly golden. Set aside to cool

Preheat oven to 425 °F (220 °C).

In a saucepan over medium‑high heat, stir pumpkin purée until it begins to darken and caramelize (~5–8 minutes), then add brown sugar, salt, cinnamon, and spice blend; stir for ~2 minutes until fragrant

Remove from heat; stir in melted butter, sour cream, heavy cream, vanilla, and eggs until smooth.

Pour the filling into prepared crust.

Bake for 15 minutes at 425 °F. Reduce oven temperature to 350 °F (175 °C) and bake for another 25–30 minutes, until the center is just set but still slightly jiggly

Remove from oven; allow to cool gradually—leave pie in turned‑off oven with door cracked for 15 minutes, then transfer to cooling rack until room temperature to help prevent cracks