Preheat the oven to 375°F (190°C). Line two baking sheets with parchment paper.
In a medium bowl, whisk together the flour, baking soda, and salt. Set aside.
In a large bowl, beat the softened butter, granulated sugar, and brown sugar together until creamy and smooth, about 2-3 minutes.
Add the vanilla extract and eggs to the butter mixture, one at a time, beating well after each addition.
Gradually add the flour mixture to the wet ingredients, mixing until just combined.
Fold in the chocolate chips evenly throughout the dough.
Drop rounded tablespoons of dough onto the prepared baking sheets, spacing them about 2 inches apart.
Bake for 10-12 minutes, or until the edges are golden brown but the centers are still soft.
Remove from the oven and allow cookies to cool on the baking sheets for 5 minutes before transferring them to wire racks to cool completely.
While the cookies cool, prepare the filling by beating the softened butter until smooth.
Gradually add the powdered sugar, vanilla extract, and heavy cream, beating until the filling is light and fluffy.
Once the cookies are completely cool, spread about 1 tablespoon of filling on the flat side of one cookie.
Top with another cookie, flat side down, to create a sandwich.
Repeat with remaining cookies and filling.
Serve immediately or refrigerate the cookie sandwiches in an airtight container for up to 3 days.