2 cups cold heavy cream
1 tbsp espresso powder
1 (14 oz) can sweetened condensed milk
1 cup chocolate chips or chunks
Whisk together espresso powder and cold heavy cream into the mixing bowl of a stand mixer. The espresso powder should dissolve into the heavy cream. If some of it remains undissolved, it should completely dissolve once you start whipping. Using a mixer, whisk on high speed until heavy cream forms stiff peaks.
Pour condensed milk into a large bowl. Add in 1/3 of the whipped cream and gently fold into the condensed milk with a spatula. While the stiff peaks won't hold their form, you still want to keep as much air as possible. Fold in another 1/3. Fold in final 1/3. Pour in chocolate chips and gently stir in.
Pour batter into a 9 x 5 metal loaf pan. Smooth with spatula or create a pattern on top if you wish. Freeze overnight to set.