Warm the milk to 95 to 104°F (35 to 40°C) and pour into the bowl of a stand mixer. Sprinkle the yeast and half the sugar over the milk. If using active dry yeast, leave to sit for 5 to 10 minutes until foamy. Instant yeast can proceed immediately. 180 g whole milk, 2 1/4 teaspoons instant yeast, 50 g granulated sugar
Add the flour, remaining sugar, pumpkin puree, egg, spices, and salt to the bowl. Fit the dough hook and mix on low speed until a thick dough forms. 500 g all-purpose flour, 170 g pure pumpkin puree, 1 large egg, 1 1/2 teaspoons ground cinnamon, 1/2 teaspoon ground ginger, 1/2 teaspoon ground nutmeg, 1/8 teaspoon cloves, ¾ teaspoon salt
With the mixer running on medium speed, add the softened butter a few cubes at a time. Continue kneading on medium speed for about 10-15 minutes, until the dough is smooth and elastic and pulls away cleanly from the sides of the bowl. To check, let the dough rest 5 minutes, then stretch a small piece. It should stretch thin without tearing (the windowpane test). 55 g unsalted butter
To knead by hand: Mix with a wooden spoon until a rough dough forms, then turn out onto a lightly floured surface. Knead in the butter a few cubes at a time and continue kneading for 10 to 15 minutes until smooth and elastic.