In a large stand mixer fitted with the paddle attachment, cream together softened European butter and sifted powdered sugar on medium speed for 2 to 3 minutes until smooth and pale. Beat in pure vanilla extract and sea salt.

Reduce mixer speed to low and gradually add all-purpose flour, mixing just until a soft cohesive dough forms. Do not overmix. Shape dough into a flat disc, wrap in cling film, and chill in refrigerator for 20 minutes.

Preheat oven to 350°F (175°C) and line two large baking sheets with parchment paper. Scoop 1-tablespoon balls of dough, roll smooth, and place 2 inches apart on sheets.

Use the back of a rounded measuring teaspoon to gently press an indentation into the center of each ball. Bake for 10 to 12 minutes until bottoms are lightly golden but tops remain pale.

While cookies bake, prepare filling: In a small saucepan over medium heat, melt 3 tbsp butter with dark brown sugar, maple syrup, and heavy cream. Bring to a gentle boil for 90 seconds until bubbly. Stir in chopped toasted pecans and cinnamon; remove from heat.

Immediately after removing cookies from oven, gently re-press indentations if slightly puffed. Spoon a warm heaping teaspoon of gooey pecan filling into each cookie well.

Whisk together glaze ingredients and drizzle lightly across cooled cookies before serving.