Preheat the oven to 350 degrees F. Line a 9-inch square pan with foil.
Whisk together the flour, baking powder, cinnamon, baking soda and salt.
Working with a stand mixer fitted with a paddle attachment, or a hand mixer in a large bowl, beat the peanut butter and butter together on medium speed until smooth. Add both sugars and beat for 1-2 minutes until well incorporated into the butter. Add the eggs one at a time, beating for 1 minute after each goes inches Beat in vanilla extract.
Reduce the mixer to low and add in the dry ingredients, mixing only until they disappear into the dough; the dough will be thick. Add the peanuts and chocolate and give the mixer a few turns to stir them into he dough. If the chunky ingredients are mixed in after a few seconds, just finish the job with a sturdy spatula-don't over mix the dough. Scrape the dough into the prepared pan.
Bake blondies for 40-50 minutes, or until they turn a deep honey brown and a thin knife inserted into the center comes out clean. Transfer the pan to a rack and cool to room temperature.
Make the ganache: Place the chocolate chips for the ganache in a heat-proof bowl. In a small sauce pan, bring the cream to a slow, gentle boil. Pour the cream over the chocolate chips and let it stand for about 2 minutes.Whisk in the butter and gently stir until the chocolate and butter are melted and the mixture is smooth.
Pour the ganache over the blondies and spread into an even layer. Refrigerate until the ganache has hardened slightly.