Preheat the oven to 350°F. Grease a 9-inch round cake pan with cooking spray. Line the bottom with a round of parchment paper and lightly spray again.

In a large bowl, add the granulated sugar, Greek yogurt, oil, eggs, and vanilla extract. Whisk together until well combined.

Add the flour, baking powder, espresso powder, and salt; use a spatula to stir until just combined. Don’t over mix.

Pour the batter into the prepared pan and bake for 30 to 35 minutes, or until a toothpick inserted into the center comes out clean.

Remove the cake from the oven and let cool in the pan for 15 minutes. Invert onto a wire rack, flip it upright, remove the parchment, and let cool completely.

While the cake is cooling, make the frosting. In a bowl, beat softened butter until smooth. Add Greek yogurt, vanilla extract, and salt, beating until smooth.

In a separate bowl, whisk together the confectioners’ sugar and cocoa powder. Gradually add to the butter mixture and beat until smooth.

Spread the frosting over the cooled cake. Serve with fresh berries, if desired.