Preheat the oven to 350°F (175°C) and grease a 9-inch round cake pan.
In a bowl, whisk flour, baking powder, baking soda, salt, and espresso powder.
In another bowl, beat butter and sugar until creamy. Add eggs and vanilla, mixing until smooth.
Stir in sour cream. Gradually add the dry ingredients, mixing until fully combined.
Fold in the chocolate chips and pour the batter into the prepared pan.
In a small bowl, combine brown sugar, flour, butter, and cinnamon for the streusel.
Sprinkle the streusel mixture over the batter.
Bake for 30-35 minutes, or until a toothpick inserted comes out clean.
Let the cake cool on a rack before serving.