Preheat your oven to 350°F. Grease and line a 9" baking pan with parchment paper; set aside.In a large bowl, combine the dry ingredients and mix with a whisk or fork until really well combined.In a smaller bowl, combine the wet ingredients and whisk until smooth and very well combined; pour over the dry ingredients and mix well with a rubber spatula.Transfer the dough to the prepared pan and spread as evenly as possible, then lightly press pecan halves across the top if desired.Bake for 23-25 minutes, or until the top is nice and golden brown and a toothpick inserted in the center of the cake comes out clean.Place the pan on a cooling rack and let the bars cool for at least 1 hour, then lift from pan and cut into 16 to 20 bars.Keep the bars in an airtight container in a cool dry place for up to a week.