Peanut Butter Brownies with Chocolate Buttercream Frosting (GAPS, grain-free)

I saw this recipe on Grain-Free Foodies and was inspired to make a chocolate-peanut butter version for my GAPS dessert quota.  They came out so beautifully!  I would even make these for company, kind of like the Lemon Curd Bars that even "regular" people like.  I tend to worry about my taste buds these days, since having been on GAPS and real food for so long I don't need as much sweetener in my desserts.  But really, these brownies are good enough for anyone to like, even if they aren't a fellow GAPSter.

Chocolate-Frosted Peanut Butter Brownies

2 1/2 cups peanut butter
1 cup raw honey
4 eggs
3/4 tsp. baking soda--optional, do not use if on GAPS

1. Preheat oven to 325 degrees.  Combine all ingredients together with a stand mixer using the paddle attachment, until the batter is well-mixed, glossy and slightly stiff.  However, do not beat too long!  If it's too stiff, then the brownies will be tough.
2.  Butter a 10x15 glass pyrex pan very generously.  Pour batter into the pan, spreading out with a spatula.  If this doesn't work, get your fingers wet with water and press into an even layer.
3.  Bake for 30-35 minutes, until golden brown and set in the middle.
4.  Let cool completely before frosting.

Chocolate Buttercream Frosting

2 sticks grass-fed butter, at room temperature

1/2 cup raw honey

2/3 cup cocoa powder

2 tsp. vanilla

1.  Put butter and honey into a bowl on your stand mixer fitted with the whisk attachment.  Whisk at a high speed for 3-5 minutes until well-combined and light colored.  Turn mixer off and add cocoa powder and vanilla.  Start mixer slow until combined, then whisk on high for another 3-5 minutes.  Turn off, scrape down the sides of the bowl and combine by hand.  

2.  Chill entire bowl and whisk attachment in the fridge for 30 minutes.  Remove and whisk once more for 3-5 minutes.  Use to frost immediately.  Store leftover frosting in the fridge.