Preheat oven to 350°F (175°C). Grease a 12-cup Bundt pan.*
Stir the pecans, butter, and sugar together with a fork. Sprinkle the mixture in the bottom of the prepared pan.
To make the cake:
Whisk together the flour, baking soda, and salt. Set aside.
Using an electric mixer on medium speed, beat the butter, brown sugar, granulated sugar, and vanilla until fluffy (3-5 minutes). Add the eggs, one at a time, beating just until blended after each addition.
Add the flour mixture, alternating with the buttermilk. Begin and end with flour mixture. Reduce mixer speed to low and beat just until blended. Mix in the chocolate chips. Transfer the batter to the prepared pan.
Bake 50-55 minutes, or until a cake tester inserted into the center comes out clean.
Cool in pan on wire rack for 10 minutes. Remove from pan to cool completely on wire rack.
Notes
*I recommend a cooking spray with flour, like Baker's Joy or Pam Baking.
Store in an airtight container at room temperature up to 3 days or in the freezer up to 3 months.