Transfer the mashed sweet potatoes to a large bowl and add the softened butter, brown sugar, granulated sugar, evaporated milk, eggs, flour, vanilla, cinnamon, nutmeg, ginger, cloves, and salt. Mix well using an electric mixer or whisk until smooth.
1/4 cup salted butter, 1/2 cup (100g) light brown sugar, 1/2 cup (100g) granulated sugar, 1/2 cup evaporated milk, 2 large eggs, 2 Tablespoons all-purpose flour, 2 teaspoons pure vanilla extract, 1 teaspoon ground cinnamon, 1/2 teaspoon ground nutmeg, 1/4 teaspoon ground ginger, 1/4 teaspoon ground cloves, 1/4 teaspoon salt