In a bowl combine pears, lemons juice, nutmeg, zest and salt. In a skillet, melt butter and honey. Add pears and sauté until the pears are just tender, 5 to 7 minutes. Remove from pan and cool. Reserve liquid in pan.

For the topping, grind in a food processor the almonds along with the flour, sugars, spices and salt. Pour in the melted butter and pulse until crumbs form.

Heat oven to 350 degrees. Butter a 10-inch springform pan; line with parchment paper and butter the paper.

Whisk together sour cream or yogurt, eggs and vanilla. In the bowl of a standing mixer fitted with the paddle attachment, mix flour, sugar, baking soda, baking powder and salt. Add softened butter and beat for 10 seconds to combine. Beat in egg mixture, continuing to beat until very smooth.

Pour batter into pan and top with the pear slices, spreading them out evenly (if there is liquid in the pan with the pears, don’t add it to cake, but add it to liquid in pan). Shred almond paste on top, if using. Use your fingers to squeeze together large crumbs from the topping and scatter evenly on top of pears.

Bake for 60 to 65 minutes, until the cake is set and the center springs back when very gently pressed with a finger. A cake tester may come out with crumbs attached, but it shouldn’t be wet. Transfer cake to a wire rack and cool completely, at least 2 hours before serving. Cake can be made a day ahead.

Heat liquid in pan and reduce it to a sirupy consistency. If cake is served with vanilla ice cream, pour pear sirup on ice cream.