cake:
½ cup well-shaken buttermilk
2 tsp finely grated fresh ginger
1 tsp vanilla extract
1 cup pecan halves, plus more for decorating the cake (optional)
¾ cup canola oil or another neutral oil, plus more for greasing pans
1½ cups all-purpose flour
1 tsp baking powder
1 tsp baking soda, sifted
1 tsp kosher salt
1 tsp ground cinnamon
1 tsp ground ginger
½ tsp ground cardamom
