Step 1

Heat the oven to 350ºF. Coat a 9-inch round cake pan with butter or cooking spray.

Step 2

Place 1/2 cup packed brown sugar, 1 stick unsalted butter, 1/4 cup honey, and 1/8 teaspoon kosher salt in a small saucepan. Cook over medium-low heat, stirring frequently, until the butter is melted and the sugar is just dissolved.

Step 3

Stir in 1 1/4 cups coarsely chopped raw pecans. Transfer to the cake pan and spread into an even layer.

Step 4

Whisk 1 1/2 cups all-purpose flour, 1 1/2 teaspoons baking powder, and 1/2 teaspoon baking soda together in a medium bowl.

Step 5

Whisk 3/4 cup room-temperature sour cream, 2 room-temperature large eggs, 3/4 cup granulated sugar, 1/2 cup neutral oil, 1/4 cup water, 1 teaspoon vanilla extract, and 1/2 teaspoon kosher salt in a large bowl until smooth. Working in two batches, stir in the flour mixture until the batter is just smooth (do not overmix).

Step 6

Stir 1/4 cup packed brown sugar and 2 teaspoons ground cinnamon together in the now-empty flour mixture bowl.

Step 7

Dollop half of the batter (about 1 1/2 cups) over the pecans, then spread into an even layer. Sprinkle evenly with the cinnamon-sugar mixture. Dollop with the remaining batter and carefully spread into an even layer, covering the sugar mixture.

Step 8

Bake until deep golden-brown and a toothpick inserted into the center comes out clean, 35 to 40 minutes. Check after 30 minutes: If the cake is browning too much, tent it lightly with aluminum foil.

Step 9

Let the cake cool in the pan for 10 to 15 minutes. Run a thin knife along the edge to loosen the cake. Invert the cake onto a large plate and sprinkle with flaky salt if desired. Let cool until room temperature. Serve with vanilla ice cream if desired.