- Preheat your oven to 350°F (175°C) and line a baking sheet with parchment paper. 
- In a large mixing bowl, use an electric mixer to beat the softened butter and sugar together until light and fluffy. 
- Mix in the egg and vanilla extract, blending until smooth. 
- In a separate bowl, whisk together the all-purpose flour, baking soda, and salt. 
- Gradually add the dry ingredients to the butter mixture, stirring until combined. The dough should be soft but not sticky. 
- Roll the dough into 1-inch balls and place them on the prepared baking sheet, spacing them about 2 inches apart. Gently flatten each ball with the bottom of a glass or your fingers. 
- Bake for 8-10 minutes, or until the edges are lightly golden. Be careful not to overbake, as the cookies will continue to firm up as they cool. 
- Let the cookies cool on the baking sheet for a few minutes before transferring them to a wire rack to cool completely.