Triple Pumpkin Crumb Muffins

Name: Triple Pumpkin Crumb Muffins
Ingredients: ⅔ cup (100 g) coarsely chopped pumpkin seeds; ½ cup (63 g) all-purpose flour; ¼ cup (50 g; packed) light brown sugar; 1 tsp. pumpkin pie spice; ½ tsp. Diamond Crystal or ¼ tsp. Morton kosher salt; 4 Tbsp. chilled unsalted butter, cut into ½ pieces; 2 large eggs; 1½ cups (300 g; packed) light brown sugar; 1 cup (230 g) unsweetened pumpkin purée; ¼ cup extra-virgin olive oil; ¼ cup whole milk; 1 Tbsp. pumpkin pie spice; 1 Tbsp. vanilla bean paste or extract; 2 tsp. Diamond Crystal or 1¼ tsp. Morton kosher salt; 4 Tbsp. unsalted butter, melted; plus more room temperature for serving (optional); 1½ tsp. baking powder; 2 cups (250 g) all-purpose flour; Nonstick vegetable oil spray; 12 paper muffin liners