Preheat the oven to 350F/177C convection (325F/163C conventional) and line a large cookie sheet.
In a medium bowl, whisk together the flour, baking powder, cinnamon and salt until they're well combined. Set aside.
1 1/2 cups (180g) all-purpose flour, 1 Tbsp cinnamon, 2 tsp baking powder, 1/2 tsp fine sea salt
Place the pecans in a food processor with about 1/3 of the flour mixture and grind until the nuts are finely ground (the flour will help it grind more fine and not clump together).
3/4 cup (82g) pecan halves
In a large bowl, whisk together the melted butter with the sugar, until they're well combined.
1/2 cup (113g) salted butter, 1 1/8 cup (225g) light brown sugar
Add the egg and vanilla extract and whisk the batter for 1-2 minutes, until it's all smooth and has lightened in color a little.
1 large egg, 1 tsp vanilla
Add the dry ingredients, the nut mixture and the shredded carrots and fold the mixture until it's all well combined.
1 1/2 cups (180g/2 medium) carrots
Use a 2 oz cookie scooper to scoop 2.4 ounces of cookie dough onto a cookie sheet and bake for 8 minutes.
Remove the cookies from the oven and bang the pan on the counter. Use a round biscuit cutter or a spatula to round the edges of the cookies and then return the cookies to the oven for another 6-8 minutes, until the edges are a little browned and they no longer look wet.
Bang and scoot again and let the cookies rest for at least 5-10 minutes before removing from the pan. Allow to cool completely before frosting.