Preheat oven to 350℉. Line an 8x8 inch brownie pan with parchment paper.
In a large bowl, sift in the flour, baking powder, baking soda, salt, matcha powder (if using it). Next, add sugar and ground pistachios and whisk together until combined.
In a medium bowl, add in the egg and lightly beat it. Then add in the olive oil, yogurt, milk, vanilla, almond extract and whisk together until smooth. Pour this mixture into your dry ingredients bowl and mix until JUST incorporated - DO NOT OVER MIX. Transfer the thick batter to the pan and spread out evenly. Bake for 20-25 minutes or until toothpick comes out clean. Let the cake sit in the pan for 20 minutes. Transfer to wire rack and let it cool completely before frosting it.
Cream Cheese Frosting:
In a small bowl, add in the cream cheese and beat until smooth. Next add in the heavy cream in two parts, beating it in until stiff peaks form. Then add in the second portion of heavy cream and beat until it thickens. Next add in the powdered sugar, vanilla and beat until smooth and thick. Spread the frosting on top of cool cake and top with crushed pistachios.