Preheat oven to 350°F. Line a sheet pan with parchment paper.
In the bowl of a stand mixer fitted with a paddle attachment, beat the butter and sugar on medium high speed until light and creamy, about 4 minutes.
Add the eggs one at a time, mixing after each. Add the vanilla. In a separate bowl, sift together the flour, cocoa powder, baking soda, and salt. Add to the mixer and mix until just combined.
Scoop by the rounded tablespoon onto the prepared sheet pan.
Bake until edges are crisp, about 9 minutes. Let cool on the pan for a few minutes, then transfer to a wire rack to cool completely.
Repeat with remaining cookie dough.
Let vanilla ice cream sit at room temperature 10-15 minutes to soften. Place a large scoop of ice cream on 1 cookie. Top with another cookie and gently press together. Roll in sprinkles, if using.
Freeze until ready to serve or serve immediately. Ice cream sandwiches will keep in the fridge for a few days (see Note).
NOTES
- If storing in the freezer for longer than one day, I recommend wrapping each sandwich in plastic wrap to prevent freezer burn.
Calories: 624kcal, Carbohydrates: 81g, Protein: 10g, Fat: 30g, Saturated Fat: 19g, Cholesterol: 127mg, Sodium: 328mg, Potassium: 423mg, Fiber: 3g, Sugar: 59g, Vitamin A: 1058IU, Vitamin C: 1mg, Calcium: 219mg, Iron: 2mg