- To make the crust, in the bowl of an electric mixer fitted with the flat beater, combine the butter, granulated sugar, all-purpose flour, rice flour, cocoa powder and salt. Mix on low speed until the dough comes together. Roll out the dough into a 9-inch round. Pat the dough into the bottom of a 9-inch springform pan. Refrigerate for at least 30 minutes or as long as overnight.
- Preheat an oven to 300°F.
- Bake the crust for 30 minutes. Let cool completely.
- To make the cheesecake, have a pot of hot water ready. In the bowl of an electric mixer fitted with the flat beater, beat the cream cheese on medium speed until smooth. Add the granulated sugar and beat until smooth. Add the eggs 1 at a time, beating well after each addition. Stir in the sour cream and espresso powder and mix until smooth.
- Spread the batter evenly over the crust. Place the springform pan in a large roasting or baking pan, then place on the oven rack. Carefully fill the roasting pan halfway with hot water. Bake for 1 1/4 to 1 1/2 hours. To test for doneness, gently shake the pan; the cheesecake should be set from the center to the edges but not dry.
- Transfer the pan to a wire rack and let cool for 30 minutes, then refrigerate until chilled throughout, about 1 hour.
- To make the glaze, in a small, heavy saucepan over low heat, combine the brown sugar, butter and cream. Heat until the sugar dissolves, then increase the heat to high and bring to a boil. Reduce the heat to medium and cook, stirring constantly, until thick and smooth. Let cool to room temperature.
- When ready to serve, remove the cheesecake from the refrigerator and transfer to a large serving plate. Cut with a hot, dry knife. Drizzle slices with the caramel glaze and dust with cocoa powder.