Preheat the oven to 350F. Grease and line an 8x8" baking pan with parchment paper; set aside.

If using, start by preparing the hot fudge sauce. In a medium saucepan over medium-low heat, melt the butter and chocolate chips, stirring frequently. Slowly whisk in the evaporated milk. Then, whisk in the sugar, cocoa powder, and salt. Cook over medium heat, until it comes to a boil. Then, reduce the heat & simmer for another 2-3 mins, stirring frequently. Remove from heat and stir in the vanilla. Allow to cool and transfer to a jar.

Brown the butter for brownies. Add the ¼ cup of butter to a saucepan over medium-high heat. Allow to melt and slightly brown, while stirring continuously (~5-8 mins). Remove from heat and set aside to cool slightly.

In a large bowl, whisk together the pumpkin puree, brown sugar, almond butter, maple syrup, eggs and vanilla until well combined. Then, whisk continuously as you stream in the slightly cooled brown butter, until fully incorporated.

Add in the cocoa powder, baking soda, and pinch of salt. Mix until just combined.

Fold in a little over half of the chocolate chips.

Pour the batter into to the prepared pan, and sprinkle the rest of the chocolate chips on top.

Bake at 350F for 25-30 mins, until set in the center.

Cool, then sprinkle with flaky sea salt. Cut into 16 squares.

Serve warm with vanilla ice cream and the hot fudge sauce, if desired.